Bully" is a very good documentary, but one that's elevated to a status beyond its apparent virtues by its sheer usefulness: This movie really does have the power to save lives. It might save 10 kids or a thousand, or maybe just one, but just that one is more than enough to justify every public-relations machination of [producer] Harvey Weinstein's master design. "Bully" will be most useful in changing the behaviors of two categories of people who aren't bullies or victims: Average kids in school. And school administrators. "Bully" will make average kids want to gang up on bullies and protect the weak. Meanwhile, school administrators will see this movie and experience horror. First, they will feel the sympathetic horror of seeing the human misery they cause when they turn a blind eye - anguish, terror, even death. But second they will feel the empathetic horror of watching the administrators in "Bully" exposed on camera, and before all the world, as smug, self-satisfied and thunderously, cataclysmically and world-shakingly useless. "Bully" follows a handful of school kids, including Alex, a shy, awkward boy who gets smacked around every day on the bus (and the camera records this); and Kelby, a lesbian in Oklahoma. As soon as Kelby came out, people in the community stopped talking to her parents.