Denmark's Lars Von Trier (Breaking the Waves, Dancer in the Dark) is the European cinema's reigning provocateur. His big U.S. release this year was the English-language, Kidman-starring Dogville. But his best was this funny, illuminating experiment with veteran director Jorgen Leth. Larkish Lars proposed that Leth remake his 1967 short The Perfect Human five times, each with bizarre restrictions: in Cuba with shots lasting only a half-second, in the Bombay red-light district, as a cartoon, etc. Whatever humiliation Von Trier imagined, Leth makes the results fascinating. So is the film that documents them. It's a kind of reality-TV show for art-movie lovers an up-market Fear Factor and, finally, proof that art is created not despite but because of the impediments surrounding it. A master class in the exasperations of filmmaking has rarely been so entertaining.