To see the island that Cast Away was filmed on, put -17.609277,177.0397 into Google Maps and zoom in all the way on satellite mode. The beach that Tom Hanks writes HELP on and sees from the peak is the eastern most part of Monuriki, Fiji.
To make himself look like an average out of shape middle aged man Tom Hanks didn't exercise and allowed himself to grow pudgy. Production was then halted for a year so he could lose fifty pounds and grow out his hair for his time spent on the deserted island. During this hiatus, Robert Zemeckis used the same crew to film What Lies Beneath (2000).
Virtually all the sound, including dialog, in the scenes on the island - about an hour and a half of screen time - had to be replaced in post-production. Sound man William B. Kaplan made a valiant attempt at getting usable sound on the island, but the nearby surf made it impossible, given that many of the scenes needed to be very quiet.
Contrary to popular belief, FedEx did not pay the filmmakers anything for their presence in the movie. The director has made this clear in a number of interviews. While FedEx was very concerned when they heard about the project, they had no objections to the finished script and offered support during filming, with the company later stating that the movie was very good for FedEx business in general and in overseas markets in particular.
In the scene where Noland squats on the ground, contemplating an item that has washed up on shore, the shot is composed as an homage to 2001: A Space Odyssey (1968), reportedly Tom Hanks' favorite film.
Early in the movie Kelly gives Chuck a pocket watch for Christmas. She explains her grandfather used the watch on the Southern Pacific (Railroad). This is a foreshadow to Chuck's later dilemma where he is stranded in the South Pacific.
A FedEx commercial during the 2003 Super Bowl telecast featured the final scene of the film where Chuck returns the package to its sender. In this version the woman answers the door; when Chuck asks what was in the box, the woman replies, "Just a satellite phone, GPS locator, fishing rod, water purifier, and some seeds. Just silly stuff."
The production employed several local Fiji islanders in the surrounding archipelago, including the neighboring Mana Island about a mile away. The locals were allowed to keep some of the supplies and tools as tokens of their help.
Some crew members were left on the island for a few days to survive and learn some skills. They used some of their survival techniques in the movie for the character of Chuck. They were: having trouble lighting a fire, opening a coconut, talking to a volleyball, collecting packages washed up on the beach, and catching fish.
In the beginning of the film a FedEx truck delivering a package to the ranch house drives under a gateway arch that has the names "Dick" on the left and "Bettina" on the right incorporated into the arch. At the end of the film when Chuck goes out to return the package to occupant of the ranch house, the portion of the arch containing the name "Dick" has been ripped out-presumable due to the divorce action being initiated during the beginning of the film.
When Chuck is aboard the doomed Fed-Ex flight, he has his shoes off and loses them in the crash. Much later in the movie when Chuck is on a plane returning to his homeland he is shown wearing shoes, one of the first signs of his lifestyle transformation.
During a Q&A session at USC, Robert Zemeckis was asked what was in the unopened package. He replied that it was a waterproof, solar-powered satellite phone. To hear him say it for yourself on the DVD, do this: Start at the Special Features Main Menu and enter the Video & Stills Galleries. When you see "Raft Escape" press left on your remote to highlight the "World Of Time" logo.
In the film, Chuck draws a picture of Kelly (Helen Hunt) on the wall of the cave. In the movie As Good as It Gets (1997), Simon Bishop tells Carol Connelly (also played by Hunt) 'you're the reason cavemen chiseled on walls'.
"Wilson" is obviously a reference to the manufacturer of the ball used in the movie. But other Wilsons have played an important role in Tom Hanks life and career. Hanks' wife is actress Rita Wilson. And in Hanks' first TV role, he played the part of Kip Wilson in Bosom Buddies (1980).
The moment before Chuck removes his tooth in the cave, he tells Wilson his dentist in Memphis is called "Dr. James Spalding". In the German version anyway, the German voice of Noland says "Dr. James Volley", maybe because only a few in Germany are familiar with the American label "Spalding". In the Hungarian version the dentist is called "Dr. James Speedo".
The trivia items below may give away important plot points.
Alan Silvestri wrote 24 minutes of score (including over seven minutes for the final credits) for a 143-minute film. Aside from the Russian chorus and the Elvis song from the beginning, there is not one single note of written musical score in the film until Noland leaves the island (1 hour and 43 minutes into the movie). Only then does the musical score come in: an oboe, piano and strings are all that Silvestri uses. Every musical cue is a variation on the same melody, which is heard in full at the end.
Near the end of the movie, Kelly explains to Chuck that during his absence, the NFL team Houston Oilers became the Tennessee Titans and narrowly lost the Superbowl by 1 yard. This is in reference to Superbowl XXXIV (played on January 30, 2000 in Atlanta) where the Titans played the St. Louis Rams and lost 23-16. The final play of the game involved Titans wide receiver Kevin Dyson receiving a pass from Titans quarterback Steve McNair but then being tackled 1 yard short of the end-zone by Rams linebacker Mike D. Jones. Tennessee could have potentially tied the game (with an extra point) or won it (on a 2-point conversion). This play has now been widely known as "The Tackle" and remains both the closest regulation end to a Super Bowl and (as of 2012) the last time the Tennessee Titans played in one.