Nail Biting

Fingernail Filter: I know its been asked many times how to quit this compulsion. While that is a concern of mine, I need to know what to do to alleviate pain in the fingers from excessive fingernail biting. What do you recommend? I've heard people say that chewing fingernails is a bad habit, and can be stopped with strong will. I don't subscribe to that, in that I've tried so hard to stop. When I'm in the car during my hour commute, I can't...