There is some compelling evidence that Tom Cruise may use a stunt butt. The buzz about the butt began when this still from the Tom Cruise movie Valkyrie hit the web.
Hollywood has jumped to his defense, saying that it was a stunt scene and that many actors wear pads to make their butts look full and beauteous. Check out the scene below. The butt scene is at the 4:45 mark. Look at his butt before and after.