Trivia: During the scene in the bar with Mystique and the prison guard, the person on the TV is Dr. Hank McCoy - this is the real name of X-Man The Beast.
Trivia: The young girl who runs through walls and soldiers when the mansion is attacked is Kitty Pryde, aka Shadowcat from the comics. She is also referenced in the first movie, as "a girl in Illinois who can walk through walls." (00:33:20)
Trivia: This is revealed on the bonus disc of the DVD. Ronnie Drake (Iceman's brother) is the one who alerts the police of the fact that there are mutants in his house when Wolverine, Rogue and Pyro are there with Bobby. On the DVD, there is a section called 'Galleries' which has a shot of Ronnie's bedroom. On his wall, there is a big poster with 'Mutants Suck.' written on it, and another which says 'Is he one of them?'
Trivia: The entire computer list that Mystique is looking at on Stryker's computer are mutants from the Marvel universe: Guthrie (2) are brother and sister Sam and Paige, Cannonball and Husk, Keniucho Harada is The Silver Samurai; Garrison Kane is Kane from the Weapon X program; Remy LeBeau is Gambit; Eric Lansherr is Magneto, though it is supposed to be spelt Erik Lehnsherr; Artie Maddicks is Leech; Jamie Madrox is Multiple Man; Xi'an Coy Mahn is Karma; Maximoff (2) are the brother and sister Pietro and Wanda, Quicksilver and Scarlet Witch of the Avengers, both are the children of Magneto; Kevin McTaggart is Proteus, Son of Moira McTaggart; Danielle Moonstar is Mirage, Psyche; Ororo Munroe is obviously Storm; Franklin Richards (You only see the "Lin Richards"), the son of Reed Richards (Mr Fantastic) and the Invisible Woman (Sue Richards).
Trivia: All of the security guards in the file (with the exception of Mitchell Laurio, who appears in the comics as well) are people who worked on the X-Men 2 film. For example, Tom DeSanto is the executive producer, M. Dougherty and D. Harris are writers, and L. Donner is a producer. (00:23:45)
Trivia: The little mutant boy, Artie, (the one with the green forked tongue) is indeed an actual character. Anyone who has read the comics knows of the "infamous" Artie and Leech.
Trivia: In the first scene where we see Stryker, where he is fingering the stab mark on the President's desk, he appears to have on a ring with the Hellfire Club's (from the comics) trident symbol.
Trivia: The foreshadowing of Jean Grey becoming Phoenix occurs throughout the movie. Whenever Jean Grey focuses on her abilities you see a flame in her eyes. eg. during the attack on the jet, in the dam spill way, and during the sacrifice.
Trivia: In the first movie Rebecca Romjin-Stamos had to wear yellow contacts. In X2, they were added digitally, that's why they look a different shade of yellow.