It's hard to imagine a sport that lets spectators get any closer to the action or the competitors than flat track roller derby.

In this violent rolling ballet, where many of the spectators bring chairs and sit right on the fringe of the track, a skater could come tumbling into your lap at any moment and make you feel like part of the action. Two hours later, you could be buying her a shot and a beer at one of the local bars where the team religiously gets together after every bout.