X2: X-Men United

On The Tonight Show with Jay Leno (1992), Hugh Jackman related a story about something that happened during the filming of the Weapon X flashback scene: while he was filming the corridor run (in which he is nude and backlit), he turned the corner and saw the female cast members, and also James Marsden's mother, waiting for him, hooting and waving dollar bills.

In Alkali Lake, as Nightcrawler and Storm are going to rescue the captured child mutants, when the camera pans to looking at the mutants with the back of the cell centre frame, you can clearly see Nightcrawler standing there before he actually teleports into the room a second or two later.

When the 20th Century Fox logo fades away, the X in the logo stays for a second longer before it also fades away.

In the American version of the movie, Wolverine asks for "something other than chocolate milk" and receives the reply "There should be some Dr Pepper..." In international versions, the replay is "There should be some soda...". In both versions, the bottle is still a Dr Pepper bottle, only the audio is altered.

Edited into Evolution in the Details: The Design of 'X2' (2003)