, I agree with Sarah, punishments aren't a great idea. In fact, the best way to get past a binge or a fall off the wagon is to refrain from beating yourself up. Admit that you had a fall, figure out how it happened (and thus how to keep it from happening again) and move on. When we start beating ourselves up, we end up just doing the same behavior for a longer time...it turns into, "Well, I'm so bad that I might as well keep being bad..." etc.
Let's be more gentle and understanding with ourselves!
We're human and make mistakes.
That said, I think rewards can be HUGE motivators!
Like you mentioned, it makes much more sense to have non-food related ones. Not only do they motivate you, but they remind you that you love other things than food and help you to associate good feelings with things other than food. It's a win-win-win situation, I think!
Here are some threads that have suggestions for non-food rewards and other ways of rewarding yourself:
Beachgal's Rewards Thread
Sflake's Rewards Thread
Non-Food Rewards Thread
What Are Your Rewards? Thread