The script was not completely finished when filming began, since the filmmakers were more focused on the story and the action, so the dialogue was mostly ad-libbed throughout filming. Jon Favreau acknowledged this made the film feel more natural. Some scenes were shot with two cameras, to capture lines improvised on the spot. Robert Downey Jr. would ask for many takes of one scene, since he wanted to try something new. Gwyneth Paltrow, on the other hand, had a difficult time trying to match Downey with a suitable line, as she never knew what he would say
Agent Phil Coulson, played by Clark Gregg, was originally a much smaller part. In fact, the character at first was only called "Agent", and as filming went on, and it became apparent with Clark Gregg's chemistry with all the other cast members, they added more and more scenes.
Jon Favreau wanted Robert Downey Jr., because he felt the actor's past was right for the part. He commented: "The best and worst moments of Robert's life have been in the public eye. He had to find an inner balance to overcome obstacles that went far beyond his career. That's Tony Stark. Robert brings a depth that goes beyond a comic book character having trouble in high school, or can't get the girl." Favreau also felt Downey could make Stark "a likable asshole", but also depict an authentic emotional journey once he won over the audience.
Paul Bettany has never seen the film, and is unfamiliar with the plot. He said J.A.R.V.I.S. was the easiest job ever, and it was almost like a robbery, since he only worked for two hours, got paid a lot of money, then went on vacation with his wife (Jennifer Connelly).
Tony Stark's computer system is called J.A.R.V.I.S. (Just A Rather Very Intelligent System). This is a tribute to Edwin Jarvis, Howard Stark's butler. He was changed to an artificial intelligence to avoid comparisons to Bruce Wayne's butler Alfred Pennyworth.
Jon Favreau shot the film in California, because he felt that too many superhero films were set on the East Coast, especially New York City. As of May 2018, only 6 of the 19 films in the Marvel Cinematic Universe have featured New York in some capacity. These being Captain America - The First Avenger (2011); The Avengers (2012); Avengers - Age of Ultron (2015); Doctor Strange (2016); Spider-Man - Homecoming (2017); and Avengers - Infinity War (2018).
In an interview with Britain's Empire Magazine, Robert Downey Jr. thanked Burger King for helping him get straight in 2003, with a car full of drugs. He had a burger that was so disgusting, it made him rethink his life, and dump the drugs in the ocean. He repeats this, with his impromptu sit-down session with the press, upon his return from captivity. Burger King also Promoted the Film with Toys based on the Picture As Well as the Sequel.
An early draft of the script revealed Tony Stark to be the creator of Dr. Otto Octavius' tentacles from Spider-Man 2 (2004). Octavius is a villain from the Spider-Man comic, but at the time, this wouldn't have been allowed as Sony was the film rights holder to Spider-Man. However, Sony and Marvel agreed to share the film rights to the character in 2015, with Spider-Man/Peter Parker (Tom Holland) first appearing in Captain America: Civil War where he's introduced to Tony Stark (Robert Downey, Jr.). Downey would subsequently reprise his role in future Marvel Cinematic Universe films alongside Tom Holland as Peter Parker/Spider-Man.
Jeff Bridges said he felt really uncomfortable not having a script or rehearsals, since normally he is very prepared, and knows his lines to the "T". But realizing it was like he was in a "two hundred million dollar student film" took the pressure off of him, and made it fun.
(at around 49 mins) When Pepper helps Tony replace his arc reactor, was filmed using a prosthetic chest, joined to Robert Downey Jr.'s own chest, and projecting out at an angle, while Robert was "in" the back of the seat, on which he was sitting. A bright light was positioned, shining on the area to hide any potential "edges" of the fake chest piece. A similar method was used in Star Trek: First Contact (1996), when the Borg Queen is introduced.
Stan Lee, the creator of Iron Man, had originally based Tony Stark on Howard Hughes, who he felt was "one of the most colorful men of our time: an inventor, an adventurer, a multimillionaire, a ladies man, and finally, a nutcase." Robert Downey Jr. further described his portrayal of Stark as "a challenge of making a wealthy, establishmentarian, weapons-manufacturing, hard-drinking, womanizing prick, into a character who is likeable, and a hero."
For the first three Iron Man movies, Jon Favreau thought of making the Iron Monger the main villain of the second film. Stane was going to be Stark's friend and confidante in the first film, but then would become his enemy in the second installment. However, Favreau was worried how to handle The Mandarin, who was to be the villain of the first film, so he decided to re-work the character into a behind-the-scenes presence, and make Iron Monger the first villain.
(at around 1h 50 mins) Just before the final press conference, Tony Stark is reading the newspaper with a grainy, amateur photograph of Iron Man on the cover. The picture is part of a video, shot by onlookers hiding in a bush during initial filming, that appeared on the Internet in 2007.
Gwyneth Paltrow only needed to travel fifteen minutes to get to the studio. She claimed that this is a part of the reason she took the role, as she could be home with her two children during the entire shoot.
There are about five sets of armor in the film, all inspired from the "Iron Man" comics: Mark I armor, Stark's first suit, is a simple suit constructed of iron. Mark II armor is a silver suit, the prototype Stark develops (this can also be counted as the War Machine armor, as Rhodes looks speculatively at it). Mark III armor is the final red and gold armor. J.A.R.V.I.S. first presents the Mark III armor in full gold, the look pays tribute to the all-gold "Golden Avenger" armor Iron Man wore early in his career. J.A.R.V.I.S. later presents the armor in silver and red, making it look almost identical to Iron Man's "Silver Centurion" armor that he wore in the 1980s.
(at around 1h 25 mins) When Pepper discovers Tony removing the damaged Iron Man armor, Captain America's shield is on a workbench. This same scene was shown in many trailers, but the image of the shield was edited out.
(at around 1h 45 mins) During the highway battle with Iron Monger, a building can be seen in the background with a Roxxon logo. In the Marvel Universe, Roxxon is a notorious conglomerate known for illegal activities, agents of which were responsible for the deaths of Stark's parents.
(at around 58 mins) Obadiah Stane plays, on the piano, a musical piece written by eighteenth century Composer Antonio Salieri. Salieri is best known as a jealous rival of Wolfgang Amadeus Mozart, and was said to have murdered Mozart (although historical records have proven that, on the contrary, both had collaborated on, and promoted each other's work on several occasions). This serves as an appropriate parallel of Stark and Stane's relationship in the film.
In the comics, Tony Stark participated (and became Iron Man) in the Vietnam War. Later, this was changed to the Gulf War. In this film, the character's origin was changed to Afghanistan, as Jon Favreau did not wish to make the film a period piece, but instead, give it a realistic contemporary look.
It took approximately seventeen years to get the film into development. Originally, Universal Pictures was to produce the film in April 1990. They later sold the rights to 20th Century Fox. Later, Fox sold the rights to New Line Cinema. Finally, Marvel Studios decided to handle their own creation.
The production met with about thirty different writers, and they all passed, as most of them felt that Iron Man was a relatively obscure character in the Marvel universe. They were also a bit nervous about working for an untried studio better known for producing comic books. Even the re-writes led to many refusals.
To prepare for his role as Obadiah Stane, Jeff Bridges read some of the "Iron Man" comic books that featured Stane. He also grew a beard and shaved his head, which he said was something he'd always wanted to do.
Agent Phil Coulson repeatedly states he is a member of the "Strategic Homeland Intervention, Enforcement and Logistics Division" (finally shortening it to S.H.I.E.L.D.). In the comics, the S.H.I.E.L.D. Agency originally stood for the "Supreme Headquarters, International Espionage/Law-Enforcement Division", then in 1991, it was revised to the "Strategic Hazard Intervention/Espionage Logistics Directorate".
Jeff Bridges, hearing that Obadiah was a biblical name, researched the Book of Obadiah in the Bible, and was surprised to learn that a major theme in that particular book is retribution, which Obadiah Stane represents. However, the name "Obadiah" means "servant and worshiper of the Lord", which Stane obviously isn't.
EASTER EGG: In the Region 1 DVD disc 1, Special Features section, there is a hidden circle icon (not Iron Man's arc generator, oddly enough) between the "Previews" and "Main Menu" items (on a DVD remote, highlight "Main Menu", then go left). Press Enter to see a video of Stan Lee and Robert Downey Jr. discussing Lee's cameo in the film.
An animatronic puppet of the Iron Monger was built for the film by Stan Winston Studios. It stood ten feet tall, and weighed eight hundred pounds, and was built on a set of gimbals, to simulate walking. It required five operators to run it.
The cave that imprisons Tony Stark was a one hundred fifty to two hundred yard-long set, which had built-in movable forks, to allow greater freedom for the film's crew. It also had an air conditioning system installed, as Production Designer J. Michael Riva had learned that remote caves are actually very cold.
According to Terrence Howard, he and Robert Downey Jr. competed physically on the set: "I'm forty to fifty pounds heavier than him, so I'm lifting and I push up about 225, and knocked it out ten times. Robert wanted to go about 235, and he did it, so I push it up to about 245. Robert and his competitive ass almost tore my shoulder trying to keep up with him!"
Originally, Iron Man's archnemesis, the Mandarin, was going to be the film's villain, but Jon Favreau felt him to be too fantastic and dated, so he was re-written into a "working-behind-the-scenes" presence. Favreau cited "Star Wars" as a case: "I looked at the Mandarin more like how in 'Star Wars' you had the Emperor, but Darth Vader is the guy you want to see fight. Then you work your way to the time when lightning bolts are shooting out of the fingers, and all that stuff could happen. But you can't have what happened in Star Wars: Episode VI - Return of the Jedi (1983) happen in Star Wars: Episode IV - A New Hope (1977)."
(at around 1h 40 mins) In the film, Rhodey (Terrence Howard) looks at the Mark II armor and says "Next time, baby!" hinting at War Machine, Rhodey's alter-ego. An animation of a War Machine suit, with a Gatling gun attached to a shoulder, can be seen in the closing credits. War Machine would appear in Iron Man 2 (2010), Avengers: Age of Ultron (2015), and Captain America: Civil War (2016).
In the comics, the chauffeur, Harold "Happy" Hogan, is a confidante of Tony Stark, who later marries Virginia "Pepper" Potts, after a tragedy draws them closer, though they later divorce. Additionally, the origin of Happy's nickname in the comics, is that he was a former professional boxer who earned that nickname, due to his reputation of never fighting back.
According to Jon Favreau, when making this film, there was a lot of pressure for it to succeed. This was particularly due to Marvel using their characters as collateral when they received a five hundred twenty-five million dollar, seven year deal, called a non-recourse debt facility, allowing them to make original films based on their properties. Marvel wanted to have complete creative control over their characters, build a film library, and greater profit potential than the deals they've inked with other studios owning the film rights to their characters. Marvel also changed its name to Marvel Entertainment, Incorporated, to establish a Hollywood presence. If the film didn't succeed, Marvel would've lost the intellectual property rights to their library.
Rock guitarist Tom Morello assisted Ramin Djawadi in composing the film's soundtrack. Morello himself has a cameo in the film as a security guard who gets killed by the Iron Monger (perhaps fittingly, since Morello is a member of the band Rage Against the Machine).
(at around 34 mins) The code that appears on the computer screen is a utility that downloads firmware into Lego robotic toy (called RCX). It may suggest that Tony Stark used this program to download firmware into his robotic suit.
In October 1999, Quentin Tarantino was approached to write and direct the film. Later, Joss Whedon, a big fan of the comic book, was in negotiations to direct the film in June 2001. In December 2004, Nick Cassavetes was hired as a director, with the film to release in 2006, but everything fell through. Finally, Jon Favreau was hired as director in April 2006.
When Robert Downey Jr. was carrying out motion-capture work on the film, he would sometimes wear the helmet, sleeves, and chest of the Iron Man armor over the motion-capture suit, to realistically portray Iron Man's movements.
The ILM animators studied skydivers performing in a vertical wind tunnel, to create Iron Man's aerial movements. Iron Man was also animated to take off slowly and land quickly, to make those movements more realistic.
There are various references in the film to the Mandarin, Iron Man's archnemesis: -The organization that kidnaps Stark is called "the Ten Rings," after the ten rings that comprise the Mandarin's arsenal (Jon Favreau has stated that The Ten Rings, in fact, works for The Mandarin). -Commandant Raza speaks of Genghis Khan and Asia. -Commandant Raza is seen occasionally fiddling with an ornate gold ring. -The rings are worn by Stark, Stane, Rhodes, and Raza (that is to say those in positions of power).
This is the only Marvel Cinematic Universe film, and the only Iron Man film, that does not feature any martial-arts fights. It is also the first of two Marvel Cinematic Universe films in which Robert Downey Jr. (Iron Man) appears, but doesn't show off his skills in the Wing Chun fighting style.
When designing Tony Stark's house, the guideline the designers were given was to make it more "grease monkey" (inventor and mechanic) than futuristic, in order to keep the film realistic. Production Designer J. Michael Riva took inspiration from the photographs of Julius Schulman, who was noted for photographs of 1950s and 1960s Los Angeles houses.
Jon Favreau was originally going to direct Captain America: The First Avenger (2011) in the manner of a superhero comedy adventure, but he instead chose to direct this film and give it a more serious tone. Ironically, Nick Cassavetes, who was chosen to direct that film, had been filled in to direct this film in December 2004.
(at around 58 mins) Obadiah brings Tony a pizza from New York City, in a box marked "Ray's". Ray's is a famous chain of pizza places in New York City. It also marks the second Favreau-directed film to refer to Ray's Pizza. In Elf (2003), it is the pizza recommended by Santa Claus to Buddy the Elf.
As a tribute to Howard Hughes, who inspired Iron Man, production was mainly based in the former Hughes Company soundstages in Playa Vista. The scene where the Iron Man Mark III armor was created was filmed in the area where Hughes assembled the H-4 Hercules airplane (better known as "The Spruce Goose").
Jon Favreau advised Composer Ramin Djawadi to keep the core of the music on heavy guitar, which he felt suited Iron Man best. Djiwadi composed the music on a heavy guitar before arranging it for the orchestra to perform.
According to the January 2012 Air & Space Magazine, Tony Starks's character was also inspired by South African born SpaceX (and PayPal co-founder), Elon Musk. A statue of Iron Man, complete with company ID, "stands guard" at SpaceX, along with a current version Cylon.
Tony Stark drives an Audi R8 in the film, as part of a promotional deal Marvel Studios made with the Audi Automobile Company. Two other vehicles, the Audi S5 Coupe, and the Audi Q7 SUV, also make an appearance in the film.
Jon Favreau played a character similar to Tony Stark, named Pete Becker, on the hit television series Friends (1994). Both Stark and Becker are rich playboys, who give up their current life to fight, Tony fights crime, while Pete fights in Ultimate Fighting. Favreau even sported Stark-like facial hair for the role.
(at around 1h 21 mins) The pilots in the F-22 jets are codenamed "Whiplash 1" and "Whiplash 2". In the Ultimate Iron Man comics, Whiplash is a super villain who possesses a pair of gloves with steel wires attached that acted as whips. Whiplash himself would appear in Iron Man 2 (2010).
(at around 14 mins) Ghostface Killah, a long-time fan of the Iron Man comics (he uses the aliases "Ironman" and "Tony Starks", titled his 1996 album "Ironman" and sampled clips of Iron Man (1966)), got a cameo as a Dubai tycoon. However, his scene was cut from the final film. Jon Favreau apologized to Ghostface and used his "We Celebrate" video in the film.
(at around 1h 4 mins) Adi Granov designed a billboard poster of Iron Man's nemesis, the alien dragon Fin Fang Foom, for the film. This poster can be seen when Stark, while testing the Mark II armor, flies straight down a road (on Stark's left side).
The leader of the Ten Rings is named Raza, after a Marvel Comics character. However, the comic version of Raza is not an enemy of Iron Man, but an alien cyborg, who is a member of the space pirate gang known as the Starjammers. The only similarity they share, is their facial disfigurement. In the comics, Raza has implants on the left side of his face, while in the film, Raza is scarred on the right side of his face.
(at around 1h 24 mins) When Obadiah Stane watches Rhodey on television, an expensive chess set is visible on the table in front of him. In the comics, Obadiah Stane was fond of playing chess, and also created a group called "The Chessmen" to attack Stark Industries.
(at around 1h 20 mins) Stark and Rhodes graduated from M.I.T. together. When Rhodes calls Iron Man, who is flying with the F-22s, a big gold ring is on the hand that he's using to hold the phone. This is MIT's class ring, the "brass rat".
When Tony flies too high, and his suit is rendered inoperable by ice, contains many similarities to the tale of Icarus. His hubris drives him to climb too high, even as J.A.R.V.I.S. warns him of the danger, in much the same way Icarus flew too close to the sun against the advice of his father, Daedalus, causing the wax holding his wings to his body to be melted by the heat.
To prepare for his role as James Rhodes, Terrence Howard visited the Nellis Air Force Base on March 16, 2007, where he ate with the base's airmen and observed the routines of HH-60 Pave Hawk rescue helicopters and F-22 Raptor jets.
According to Phil Saunders, Tony Stark would develop a Mark IV armor, which would have been used in the final battle. This Mark IV armor would become the War Machine armor, and had swap-out armaments that would be worn over the Mark III armor. However, halfway through pre-production, the concept was removed from the script.
Production Designer J. Michael Riva, researched on objects found in prison which could be improvised and used for other purposes (for instance a sock used to make tea), to provide more verisimilitude to the film.
(at around 26 mins) While playing backgammon with Yinsen, Stark says "Sheesh o Besh. "This is a Persian slang phrase which means a roll of six and five ("Sheesh" is Persian slang for six, "o" means "and" and "Besh" is Turkish for five). Shaun Toub, who plays Yinsen, is of Persian ethnicity.
The film had a torturous development process. Stuart Gordon was originally going to direct in 1990 when the rights were held by Universal, though nothing came of that. In 1996, 20th Century Fox acquired the rights with Nicolas Cage expressing an interest in the project. Two years later, it hadn't moved on so Tom Cruise tried to kickstart a production, to the extent of commissioning a script by Stan Lee and Jeff Vintar. Jeffrey Caine then did a polish on the screenplay. Still nothing. In 1999, Quentin Tarantino was approached to see if he could move things along but that too came to nothing. The rights moved to New Line in 2000 with Ted Elliott, Terry Rossio and Tim McCanlies writing a screenplay (this version even featured a cameo by Nick Fury). New Line started talking to Joss Whedon about directing but this didn't pan out. By 2004, Nick Cassavetes was attached as director but when this too failed, the rights reverted back to Marvel.
The English translation of the Hungarian dialogue when Tony and Yinsen are about to break out of the cave, is this: Man from outside: Yinsen, Yinsen! Stop! Show your hands! Yinsen: One minute, one minute! Man from outside: Come over here right now! What is going on in there? What is going on in there? Hands up.
Screenwriters Mark Fergus and Hawk Ostby worked separately with Jon Favreau compiling both scripts, and then handing it over to John August for a polish. This is actually fairly common practice for Hollywood blockbusters.
When Pepper Potts is downloading a set of secret files, the authorization on one document is listed as "Lebowski". Jeff Bridges, who plays Stane in this film, previously had the title role in "The Big Lebowski".
(at around 49 mins) During the Mad Money w/ Jim Cramer (2005) segment, the upper (NYSE) and lower (NASDAQ) tickers are filled with quotes of fictional companies named after various Mad Money production staff such as George Manessis (Segment Producer) and Regina Gilgan (Executive Producer).
(at around 4 mins) The headlines on the magazine covers shown right before Tony Stark is presented with his award at the beginning of the film: Wired: "The Mind Of Tony Stark", Newsweek: "WHAT'S NEXT A New Superpower Steps Up", and "The Interim President Obadiah Stane To Lead Stark Industries", Popular Mechanics: "METAL VS. WOOD, Sharpen Your Skills", "Chip Off The Old Block, Six year old Tony Stark builds first V8", "Will the Arc Reactor save all our energy needs?", and "BACKYARD ROCKETS", Forbes: "THE NEW KID, Tony Stark takes reigns at 21", "Technology, The Information Superhighway", "Industry, The Defeat Of Braniff", and the Rolling Stone Special Double Issue: "TONY STARK Wants To Save THE WORLD".
When Col. Rhoades hands Tony the award, it is either a goof, since Tony doesn't like to be handed things directly, or it indicates that Tony trusts him like Pepper or Happy since his anxiety/phobia didn't take place.
The Stark Industries weapons the terrorists are carrying are actual weapons, but mostly made by German arms firm Heckler & Koch. Many of the terrorists are carrying H&K G36 assault rifles or the smaller UMP sub machinegun. A few are also using Colt M-4s (or various M-4 clones) with various accessories, include ACOG optics, PEQ-2 Infra-Red illuminators, and notably, one terrorist has an M-4 carbine with a 12 gauge Lightweight Shotgun System (LSS) mounted underneath the barrel.
As Tony is about to test his completed prototype suit, one of the sound effects heard as he boots up J.A.R.V.I.S. and mapping radar, is the "ship zap" effect from the classic arcade game "Space Invaders".
Paramount Pictures also released some of the earliest animated Superman shorts. Superman was published by Marvel's long-time rival DC Comics, before it was purchased by Warner Brothers, and Marvel purchased by Disney.
The F-22, in the close-up ground shots, is serial number 6, deployed to Edwards Air Force Base. This is one of the last "pre-production" F-22s, and is one of the first fully operational aircraft. (The first five airframes were later retrofitted to also be fully operational). Interestingly, the pole model outside of Stark Industries is labeled as "YF-22", meaning the first flying prototype for the competition between the YF-22 and the Northrop YF-23. The size of this pole model, indicates that it may be one of the original wind-tunnel models.
The terrorist organization "Ten Rings" is a reference to Iron Man villain Mandarin, who wears ten rings imbued with superhuman abilities. Mandarin appears in Iron Man 3, albeit in a radically different iteration from the comics.
When Tony first tests his hand repulsors in his lab, he ends up in front of a bookcase that has several plane models on top of it, including a C-130 Hercules. The model at the far left is an XB-70 Valkyrie, a jet developed by the military in the late 1950's and intended as a bomber, capable of Mach 3+ (three times the speed of sound). It never became operational, but the design inspired the Air France Concorde SST, a Mach 3 passenger jet in the 70's and 80's.
Stan Lee: (at around 1h 8 mins) Comic writer Stan Lee appears at Tony Stark's party playing the role of Hugh Hefner, accompanied by three blonde women. Lee later mentioned that it was his most fun cameo.
The trivia items below may give away important plot points.
During the final battle, there was originally going to be a sequence where Tony, in the Iron Man suit, drives an Audi R8 that would crash into Iron Monger's legs then flip over, after which Iron Man would split the car in half and jump out. However, the Audi R8 was so well-built, that it refused to flip, despite repeated crashes and the roof wouldn't split the way Jon Favreau wanted it to, because the car's frame was so tough. As a result, the whole final fight sequence was re-written. The filmmakers were so impressed by the toughness of the car, that it was decided that the convertible version was to be featured in Iron Man 2 (2010).
In the Ultimate Marvel Comics series, the character of Nick Fury is portrayed as African-American, with his look and personality tailored after Samuel L. Jackson, all carried out with Jackson's explicit permission. During one of the Ultimate Avengers issues, while discussing the possibility of a movie being made about them, and which actors would play which heroes, Nick Fury comments that nobody else but Samuel L. Jackson could play him. Jackson, himself a comic book fan, plays Fury in this film. Later on, the popularity of this character led Marvel to introduce this character into the mainstream comics as "Nick Fury, Jr.", the son of the original Nick Fury, in a move to work towards retiring the original from the mainstream universe.
Brian Michael Bendis had written three pages of dialogue for the Nick Fury scene, out of which the filmmakers chose the best lines. To keep it a secret, the scene was filmed with a skeleton crew, and was omitted from all previews of the film, which thus maintained the mystery and surprise, and kept fans speculative and interested. It conclusively appeared in the final cut as a post-credits scene.
When presented at the movie's end, with the cover story by S.H.I.E.L.D. Agent Coulson, that Iron Man is employed by Tony Stark to act as his bodyguard, Stark dismisses it as "pretty flimsy". In the Iron Man comics, this was precisely the cover that Tony Stark used to protect his identity, until 2002, when Stark went public with his identity as Iron Man.
(at around 1h 40 mins) When Tony Stark tells Rhodey to "keep the skies clear" before going to confront Obadiah Stane, Rhodey looks to the silver Mark II suit before saying "next time, baby". Rhodey dons this suit in Iron Man 2 (2010), becoming War Machine.
According to Jeff Bridges, Obadiah Stane was originally supposed to survive the final battle against Tony, with the heroes opening up his destroyed suit to find that there was no corpse inside. Presumably this would have poised Stane to return for future movies.
According to Jon Favreau, it was difficult to find a proper opponent for Iron Man to face, since he wanted the film to remain grounded in reality as much as possible. It was decided to have a foe in the film who would serve as a parallel of Stark (for example, an armored opponent). Well-known enemies like the Titanium Man and the Crimson Dynamo were considered, but finally the lesser-known Iron Monger, Obadiah Stane, was chosen as Iron Man's adversary (Stane, as well as possessing his own armor, is also a business contemporary of Stark).
(at around 47 mins) Obadiah Stane tells Tony Stark "We're iron mongers, we make weapons." Stane's supervillain moniker is the Iron Monger, and thus foreshadows Stane's own transition in the film to an armor-clad antagonist.
(at around 1h 55 mins) The final scene, in which Tony reveals to the press that he is Iron Man, is a reference to the Avengers Disassembled mini-series. In the mini-series (part 1), which was written by Brian Michael Bendis, Stark, under the influence of Scarlet Witch, revealed himself to be the Secretary of Defense to the entire delegates of the U.N., with the exact line spoken in the film.
The climactic showdown in the film, with Tony Stark, a.k.a. Iron Man, facing Obadiah Stane, a.k.a. Iron Monger, is based on Iron Man #200 (November 1986). A faceoff occurs between Stane's larger, more powerful Iron Monger and Stark's greater experience, and an exploding reactor appears. However, the comic concludes with Stane committing suicide with a repulsor ray blast to the head.
Tony Stark says "I am Iron Man" in the final scene. This is an homage to the series Iron Man (1994), whose theme song had the lyrics "I am Iron Man!" or the popular song "Iron Man" by the band Black Sabbath.
(at around 1h 55 mins) Shortly into the credits sequence, there is an animation of the Ten Rings logo. This refers to the terrorist group that captures Tony Stark early in the film, but is not actually acknowledged. It is, however, commonly acknowledged in Iron Man Three (2013).