A gimmicky documentary by Penn Gillette and Paul Provenza built around the ultimate obscene joke, which depends on a performer’s style and a certain amount of embroidery to achieve maximum impact. The idea is to set about 100 stand-up comics loose on this material, but the results are predictably so sound-bitey that only a few of them get to tell the joke all the way through, and many just offer commentaries. One sympathizes with Don Rickles’s complaint that this is the sort of movie whose performers don’t get paid. But with such participants as Hank Azaria, Shelley Berman, George Carlin, Carrie Fisher, Whoopi Goldberg, Eric Idle, Bill Maher, Michael McKean, Chris Rock, Jon Stewart, Dave Thomas, and Robin Williams, you won’t be too bored. R, 92 min.