In the final scene where a few seconds of the original taped-over footage of Rob & Beth in the Coney Island Ferris Wheel is shown, the camera, looking out to sea, appears to inadvertently catch the dysfunctional satellite that plummeted to Earth and woke the monster sleeping in the sea for thousands of years.
Lizzy Caplan (Marlena) did not know what she was auditioning for. She thought it was a romantic movie until her second audition, where she read a scene from Alias (2001). It wasn't until after she was offered the role that she found out it was a monster movie, and the actors weren't allowed to read the script until after they signed on.
Images from King Kong (1933), The Beast from 20,000 Fathoms (1953), and Them! (1954) are hidden within the film. Each image is seen extremely briefly, for only a single frame, during a camera edit. The "Them!" picture is shown at 00.24.06, the "Beast from 20,000 Fathoms" picture is shown at 00.45.27, and the "King Kong" picture is shown at 1.06.55. A brief clip of Rob and Beth at a train station is seen with the "King Kong" image at 1.06.51.
All the main characters (and Jamie) have MySpace pages. The producers made these pages to advertise on MySpace. All the characters last logged into them on January 18, 2008. (1-18-08), the release date of the film.
The first trailer for this movie played before Transformers (2007). It showed a giant explosion in the heart of New York City and the Statue of Liberty's head being thrown down a street. It was shot with a hand-held video recorder. There was no title.
The decapitated head of the Statue of Liberty in the street is inspired by the poster for John Carpenter's Escape from New York (1981), which depicts the head of the Statue of Liberty lying in the middle of the street.
The head of the Statue of Liberty is shown about 50% larger than actual size. CG supervisor David Vickery said in an interview that many people imagined the head being much bigger than it actually is, and that the size was increased due to complaints that the head looked too small in the trailer.
The rats used in the tunnel scene were specially-trained and colored with a dark, charcoal-like substance to give them the appearance of wild, dirty tunnel rats. The rats in the final shot were completely computer-generated.
The movie is viewed primarily from the point of view of Hud, the character who uses the camera the most. H.U.D. is short for Heads-Up Display, a method for overlaying information onto a view of one's surroundings such as Timestamps on video footage.
The film was shot in 34 days, in Los Angeles under the fake title "Slusho" and in New York under the fake title "Cheese". The Ferris wheel scene, the last in sequential order, was filmed on the first day. The scene inside Beth's parents' apartment, the first in sequential order, was filmed on the last day.
At the beginning of the film there is a textual reference to DARPA - The Defense Advanced Research Projects Agency which is an agency of the United States Department of Defense responsible for the development of new technology for use by the military.
When the teaser trailer with the head of the Statue of Liberty was shown without a film title, but a reference to J.J. Abrams, many Abrams fans looked to the internet to find out as much as possible about the upcoming, mysterious film. Abrams launched a viral campaign using multiple internet websites to promote this film, each providing background details of the plot. However, given the mysterious nature of the film and the viral websites, a number of theories were promoted on the blogosphere that were eventually proven untrue; for example, one hypothesis involved three Biblical monsters, one each for the sea, the land, and the air, instead of the single monster that came onto land from the depths of the sea.
The crossfire sequence was shot in one night on the Warner Brothers New York Street lot in Burbank. The extras playing soldiers fired real blanks from their weapons for the first couple of takes until 10:00 pm, when noise ordinances forced them to use quiet flash bulb alternatives.
One of the promotional websites, Jamieandteddy.com (password "jllovesth"), shows videologs (vlogs) made by the title couple about their relationship (which turns sour). Jamie Lascano is only seen at the party unceremoniously unconscious on the couch, and Teddy Hanssen is nowhere to be found (although on 1-18-08.com, he is now identified as "missing"). The actors who play either of the two are not confirmed. Though it has been speculated that Jamie is played by Blake Lively, this is incorrect.
J.J. Abrams has used the number 47 extensively on past projects. In Alias (2001) it played great importance as a page on Rambaldi's manuscript, and as a recurring pointer to important motifs. It should come as no surprise that "Cloverfield" is the designation to the case of the images found on Area US-447. Also, in the scenes where they're taking the stairs up to the top of the skyscrapers to save Beth, one of the floor numbers filmed is the 47th.
The only "score" composition for this film is an instrumental piece by Michael Giacchino played over the end credits, titled "Roar! (Cloverfield Overture)". This composition was intended to evoke the score of classic monster movies of the '50s and '60s (e.g. Godzilla). Roar! was not included on the soundtrack CD (which was packaged as a mix CD of music from Rob's surprise party), and as of 2011 has not been officially released on CD, but it was included when the soundtrack collection was later released on iTunes.
Jason (Mike Vogel) can be seen wearing a Slusho! T-shirt throughout the movie. Slusho! is a drink from J.J. Abrams' show Alias (2001) as well as a codename of the film's, and the shirt is the only time the beverage is acknowledged during the movie, with far more information hinted about it on the Internet.
According to Annie Pomeranz - visual effects producer - puppets were used in the scene involving the "parasites" inside the tunnel but the scene turned out to be more interactive than originally thought and CGI animation was required. However, Matt Reeves - the director - states that the scenes with the puppets were too "goofy".
In the beginning of the movie, Beth, played by Odette Annable, talks about how she could see the footage Rob was taking on the internet. Yustman also starred in a movie called Reckless Behavior: Caught on Tape (2007), in which she plays a teacher whose career is ruined when a video of her winds up on the internet.
Jamie, in her brief appearance passed out on the couch at the party, is wearing the same outfit she wore in her video #11 on jamieandteddy.com. In the video she mentions "this thing" Lily put together and that she's going to it (evidently the party).
Many scenes were shot with the Panasonic HVX200 "prosumer" digital video camera. Visual effects plates were shot primarily with the Thomson Grass Valley Viper Filmstream digital video camera; the effects camera in NYC was the Sony F23 digital video camera.
The trivia items below may give away important plot points.
After viewing a cut of the film, Steven Spielberg suggested giving the audience a hint at the fate of the monster during the climax. This resulted in the addition of the broadcast overheard on the military helicopter's radio, as well as the sounding of air raid sirens, both to signal the forthcoming "Hammerdown" bombing mentioned earlier in the film.
It was originally intended for the Brooklyn Bridge to be destroyed by one of the monster's hands, but it was decided that this seemed too deliberate. It was changed to the monster's tail destroying the bridge, which seemed more accidental.
Hud was originally going to survive, but producer J.J. Abrams suggested having him being eaten by the monster, allowing the audience a somewhat vicarious experience. The scene was then planned as having Hud being eaten instantly after turning around, but it was decided that the audience deserved a good look at the monster, which resulted in the longer shot with the monster leaning down to inspect Hud before biting and killing him.
According to Director Matt Reeves in the DVD documentary, the last shot of the film, when Rob and Beth are on Coney Island, was the very first shoot of principal photography, while the very first scene in Beth's dad's apartment was the very last shoot of principal photography.