Here's a couple of videos from "Psycho Beach Party", filmed in 2000. Amy Adams shows off her dancing skills in the first video -- an absolute must see! EDIT: the sound doesn't seem to work in the second clip so I'm gonna try to upload it again. sorry about that!
The movie stars Lauren Ambrose as Florence Forrest, a not-so-innocent girl in 1960's Malibu who becomes "Chicklet" the first girl surfer at Malibu Beach, only Florence suffers from dissociative identity disorder and occasionally her alter ego Ann Bowman, a sexually aggressive, foul-speaking girl, comes out in which during that time several beach goers are found murdered.