Trivia: When Jack Black is singing the tune from "The Graduate" in the video store, the guy who tuts and gets annoyed is Dustin Hoffman, who starred in the Graduate. Apparently his cameo was unplanned, he noticed the cameras and stopped by, and it was decided he should make his small appearance.
Trivia: The sorority mom, Andrea Martin, is also one of the girls in the original "Black Christmas". Her name in the original was Phyllis.
Trivia: Abigail Breslin, who plays Trish the elf girl, is the younger sister of Spencer Breslin, who plays Curtis.