exercise (esp. abs)

Is anyone else anxious to get back in shape? My surgery was three months ago (DaVinci) and I was told it was fine to resume exercising but "take it easy". I've been walking on the treadmill and lifting light weights, but nothing for my abs (the few times i tried a plank position or crunch my body rebelled so i gave up). I didn't gain any weight after the surgery due to careful eating, but i feel very flabby, out of shape, and just plain unattractive.

anyone know if it's safe to do ab work? or how about yoga? i was thinking of starting a yoga class (mostly for mental benefits) but am afraid of all the twisting/stretching.

I have started doing some very mild ab work; crunches, girlie pushups, and at very low reps. So far so good. I do get a little soreness here and there, but I think that is an inevitable part of healing.