wrap it up in a ace bandage.

Jah,
Alternate ice pack for 20 min. with barely tolerable heat for 20 min. x3 daily minimum. Keep foot elevated as much as possible. Call me in the morning.

JAH, if you injured it in the last 24hrs take Jack's advice and ice it for up to 20 minuets at a time then off for at least 20 min and ice again. Take a non aspirin anti inflamatory such as Tylenol or Advil according to it's directions, and keep elevated as much as possible. All of these actions keeps swelling down, which is important to promote healing. Most important of all stay off of it. I healed a sprained ankle in two days to the point of walking without pain by staying completely off of it. Use crutches, hop get a wheelchair, have someone carry you, but don't let it touch the ground for at least 2 days. Then wrap well and use it with great caution and only after your Doctor has checked it to make sure there isn't a hidden fracture. You can only tell with x-rays. Good luck.

Jah,
Good answers above.
By now, your tournament is over and it is a good idea to rehab your ankle with a few strengthening drills so as to prevent recurring injuries.

I hope this quick vid helps with these exercises:
http://www.youthfitnessmag.com/sprained-ankle-rehab

Cheers