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: 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.