Trivia: The Scarecrow's plot to contaminate Gotham's water supply from under Arkham Asylum has appeared several times in Batman fiction, first appearing in the comics and becoming the focus of the Batman: The Animated Series episode 'Dreams In Darkness'. After the film was released it would also be referenced in the Batman: Arkham Asylum videogame.
Trivia: Director of Photogrophay Wally Pfister used several interesting filming techniques on the film, eventually earning him a "Best Cinematography" Oscar nomination. One of these was how he shot the sword duel between Bruce and Ducard - holding a steadicam and being dragged around the action sitting on a sled.
Trivia: The first thug we see Dr. Crane get off with an insanity defense is named Zsaz. If you look closely you'll see he is covered with scars. In the comics, Zsaz is a homicidal maniac who keep score of the people he kills by marking it on his skin. Every one of those scars is supposed to represent one of his victims. And although you don't see it in the movie, his body is covered.