Trivia: The two old men near the end, talking about it being "old school" are voiced by Frank Thomas and Ollie Johnston, two Walt Disney animators who worked on such classics as Bambi and Cinderella.
Trivia: In Carlotta's dressing room there is a large portrait of Carlotta holding Andrew Lloyd Webber's head on a plate.
Trivia: At the ranger's office when the security guard was stealing the medical supplies, you see a cameo of M. Night Shamalayan in the reflection of the glass.
Trivia: When Mort smashes the shower door, the hole left in the glass looks like a small, four-legged animal with a screwdriver in its neck - which is how Shooter kills his dog.
Trivia: The bloated woman who is brought into the mall in the truck is actually played by a man. His name is Ermes Blarasin, and he is a stuntman.
Trivia: There is a party at J.D.'s school after the academic decathlon. Most of the students are wearing name tags. Sam's name tag says "Hello my name is Yoda." (00:21:50)
Trivia: Christian Bale dropped approximately 60 pounds for the role, going from 180 to 120, by eating a diet of one can of tuna and an apple a day for months. This is the most weight ever lost by an actor for a film role. Within 6 months of this film he then put on 100 pounds to play Batman in Batman Begins. He actually gained so much weight he was too big for the batsuit and had to drop 20lb for filming.
Trivia: Spider-Man creator Stan Lee makes his standard cameo appearance for this film when Spider-Man and Doc Ock are fighting on the side of the building. The first shot of the street during the fight shows a woman being pushed out of the way as some debris falls; the man pushing her is Lee.