Trivia: The dolphin was trained to retrieve many objects that were thrown in a pool at SeaWorld Miami. There were maybe 12 -16 different shaped and weighted items that she learned to pick up and place on the side out of the pool and water. One of the objects and the most important was a black rubber gun. Every single time the only object she would not recover was the gun.
Trivia: Willem Dafoe was asked to play Donald Kimball in 3 different ways: he thought Bateman was guilty, he didn't think Bateman was guilty, and he wasn't sure if Bateman was guilty. They were all blended together to make the audience not know what Kimball thought of Patrick Bateman.
Trivia: Some of the members of Captain America's wartime elite squad are taken from Marvel Comics WWII based "Sgt Nick Fury and the Howling Commandos" - such as Dum Dum Duggan and Gabe Jones.
Trivia: The topless girl at the mobsters' pool party is future "Three's Company" TV star Suzanne Somers.
Trivia: In the scene where Regan's mother is supernaturally blasted away from the bedside, she is being yanked by the crew by a length of rope. After dozens of takes director William Friedkin was still unhappy with the look of the shot and ordered the crew to haul her more fiercely. The scream in the shot that made the cut was of genuine pain and required no dubbing for effect.
Trivia: Penelope Cruz played the same character in 'Vanilla Sky' as she did in the Spanish version of the same film, 'Abre Los Ojos'.
Trivia: None of the moths seen in the film are actual Death Head moths. In the interest of avoiding the hassle involved with actually shipping moth eggs over, then halting filming so they could be raised to the proper level of maturity, the production crew simply went with a similar looking domestic breed of moth, and glued false fingernails painted with the trademark skull like visage onto their bodies.
Trivia: Jennifer Garner wore colored contacts for the role of Elektra. Her natural eye color is brown.
Trivia: After the truck with the gold in it, drops from the street and people scatter and scream, there is a man dressed as Spider-Man on the street. (01:25:35)
Trivia: There are lots of signs showing how Evan will die: the doll in the hallway is missing its right eye, the fridge magnets spell 'eye' after one falls off and lastly he has just bought an 'i' Mac computer.
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: Laurence Mason's character Lord Nikon was given the name because of his photographic memory.