Arnold Schwarzenegger's cameo was filmed the same day he filmed his appearance as the Terminator for the Super Bowl. It was completely unprepared. He happened onto the set that day and was asked to make a quick appearance in the film. Fans and movie enthusiasts often cite his saying "Have fun" to Dwayne Johnson as a passing of the torch to an action hero of the next generation.
According to director Peter Berg, they were scouting a location in the Amazon forest of Brazil when they were held up at gunpoint by three locals and robbed of all cash, computers, and other valuables. After that (probably a joke) the shoot location was changed to Hawaii.
Konlabos, the fruit used to paralyze Dwayne Johnson and Seann William Scott's characters, is actually a fruit called chirimoya or custard apple, depending on where you buy it. This fruit does not cause paralysis and is actually eaten all over the world for its delicate flavor.
When Christopher Walken is delivering his speech about keeping his eye on the ball, the images that are shown of the gold mine workers are a reference to a series of photos from the 1980s by Sebastião Salgado that were taken at a famous Brazilian gold mine, called "Serra Pelada".
According to director commentary on the DVD, Christopher Walken had never seen Willy Wonka & the Chocolate Factory (1971) and was therefore reluctant to use the phrase, "Oompah-loompahs" in his final scene. The director provided Walken with a copy of the movie, and after watching it, Walken decided to use the phrase.
Hatcher's tooth-fairy speech was a substitution for him comparing the situation to Pooh stuck in the door to Rabbit's house from The Many Adventures of Winnie the Pooh (1977) after Disney threatened to sue over it.
Both of the film's previous working titles are referenced in the film. After arriving in Brazil, Beck passes a sign that reads "Helldorado", and in the jungle, Travis tells Beck, "Welcome to the jungle..."
There are several references to Dwayne Johnson's wrestling persona. He uses his signature wrestling move the Rock Bottom on a thug. The herd of bulls connects with his Brahma bull tattoo. His character (Beck) wants to be a cook at his own restaurant, referencing his catch phrase: "If you smell what The Rock is cooking!" this is also a reference to Robert De Niro's character Jack Walsh, who is doing one last rundown to open his own restaurant in Midnight Run (1988), which is what this film is loosely based on. Also, the monkey scene refers to his monkey jokes (telling people to go suck a monkey's nipple).
The rifle that Mariana uses to nearly shoot Travis is a 7.62x39 SKS Sporter edition. The standard SKS had a built in, non-removable 10 round magazine, while the sporter edition took the AK-47 magazines (which replaced the SKS).