I agree with Russell- we all make mistakes, you just need to vow to do better tomorrow.
Rather than punishment, focus on prevention. Try to figure out the circumstances where you binge and change them. If having the stuff in the house is the problem, remove the temptation. If its because you're depriving yourself, build in small treats throughout the week or a "cheat" day (which might actually help your metabolism too!) If it happens when you let yourself get too hungry and there's nothing else available, work on planning your meals ahead of time or having healthy snacks available that will fill you up. If its emotional eating, figure out in advance something that you can do when you feel the urge arise- take a walk, dance to your Wii, call a friend or something else that can distract you. I've read that if you distract yourself for even a few minutes, the impulse to eat will often disappear as quickly as it came on.
The most important thing is that when you screw up (and we all do!), pick yourself up as quickly as you can and get back on the wagon. When you realize you're in a hole, stop digging! And keep in mind that you have to consume an extra 3500 calories to put on a pound. Easy enough to do in a week, month or year but the damage you can do in one afternoon is pretty minimal.