Comedian Paul Provenza and gonzo magician Penn Jillette directed and produced this incapacitatingly funny documentary about the world's filthiest joke. Hundreds of comedians (from Robin Williams to Jon Stewart to the Smothers Brothers to Chris Rock to Whoopi Goldberg to Andy Dick to Phyllis Diller to Sarah Silverman to the kids from "South Park") each tell their own version of the classic showbiz joke. The joke isn't even that funny; the point is to spin it off on your own nasty little rant, with some legendary comedians able to tell the joke for more than an hour. While watching hundreds of comedians recite the same punchline over and over again sounds mighty boring, the film is an amazing look at how art (in this case, comedy) is created. Keep in mind, if you don't have a filthy, disgusting and totally prurient sense of humor, you will be mortally offended. If, on the other hand, you like your jokes as dirty as possible, this amazing examination of language and humor is a gut-buster from start to finish. For God's sake, there's a mime telling the joke--and even he's funny! 92 minutes Unrated.