You'd be suprised how many excercises there are for abs, other than sit-ups. I do x-country, and after every practice we do abs. Sit-ups aren't that great if you're serious about getting a six-pack, and crunches aren't much better, by them self, since they only work your upper abs. I'll try my best to explain them, but some are sorta hard to describe in words. To maximize the benifits of a normal sit-up, do "pray" sit-ups, which involes getting into the usual position, then putting your hands together as if praying, and placing them under your chin, which your arms glued to your stomache. This eliminates the tendancy to use other muscels besides your abs when doing push up. A similair one is doing a normal sit-up, except alternating reaching up with your hands as if there was a rope hanging down between your knees. You can also isolate one side of your abs, by getting into normal sit-up position then turning the lower half of your body to the side. Doing a set of these (make sure you do both sides, so you don't get lopsided) is much more benificial then a set of normal sit-ups. A more obscure exercise is the "squirm" which involves sitting down, then leaning back slightly and lifting your legs off the ground (the higher the better), then twisting your upper body back and forth as far as you can. Do this for a minute or so and I'm sure you'll feel the burn. Most of these xcersizes can be improved trhough the use of a medicine ball, which adds some wieght resistence. I hope this helps, and if you have any questions, feel free to ask. Sorry for any typos.