There are a lot of little coping techniques I've amassed over the process. They don't always work, as the anxiety sometimes gets the best of me, but making an attempt is always worth a shot. Here's my list:
1. Exercise at least twice a week (though three times a week is better, and every day is optimal (for me)). I find I feel much better after a good workout, and it helps clear my mind. Spending an hour a day at the gym is wonderful because it's time to focus on yourself, your body, and your own thoughts. Don't overextend yourself, but push yourself hard enough to make it worthwhile. I like to alternate cardio/weights days with yoga days.
2. Spend as much time as possible with friends. They are good at distracting me, making me laugh, letting me vent when I need to, forcing me to concentrate on work (study groups are an excellent way to get your mind off the application process - when you're in a small group of people, you really have to focus on the material at hand) and just being in the room to stop focusing on my crap and realize that there are other important things in life.
3. Drink tea (especially herbal). It's calming and soothing.
4. Get away from the computer! Force yourself not to read this site for a while...it's less stressful when it's not present.
5. If you can, try reading an absorbing book or magazine that has nothing to do with science or the medical world. Just block it all out for as long as possible. Other options: do an absorbing activity you enjoy (for me, it can be the NY Times crossword puzzle, a particularly challenging new recipe, some mindless shopping, etc).
6. Vent. Don't keep it all bottled up inside; you'll feel a lot less anxious after you share your worries and thoughts with someone.