Ive actually been interested in this as well due to having broke one ankel and majorly spraining and rolling them on a regular basis.
http://www.bodybuilding.com/fun/betteru49.htm
http://stacktv.stack.com/video.aspx?...3575487001_583
1. Single leg balance: Without any support, stand on one leg for 30 seconds. Repeat six times with each leg. Begin with your eyes open, then progress to standing with your eyes closed. Once your master that, move on to standing on a slightly bent knee.
2. Toe-Heel: Sit in a high chair so that your foot comfortably hangs approximately two inches off the ground (use a stack of books on a chair to get the height set). Rhythmically tap your toe and then heel on the ground, trying to isolate all movement in the ankle. Start slow and build up speed to produce a fast but rhythmical tapping. Do 3 sets of 50 reps.
3. Side-to-Side: In the same sitting position and rhythm as Toe-Heel above, touch the outside edge of your foot on the ground and then your foot's inside edge for one rep. Again, start slow and isolate the moment in the ankle as best your can. Speed up the rhythm as your coordination improves. Do three sets of 50 reps.
4. Wobble Board: Sit in a chair and place one foot in the center of a wobble board or Bosu platform with 360 degrees of rotation. Rotate the foot in a circle so the edge of the wobble board comes close to the floor but doesn't touch. As your balance and coordination improves try standing on the wobble board with one leg. Do two sets of ten of the following motions for each foot: a. Forward-Backward, b. Side-to-Side c. clock-wise and counter-clockwise