lay down on the floor, flat.
raise your legs straight up in the air, hands flat on the ground beside you.
have someone straddle over you and as you bring your legs up, have the other person PUSH YOUR FEET AWAY TOWARDS THE FLOOR as hard as he/she can, BUT DONT LET YOUR FEET TOUCH THE FLOOR.
start out doing only 10 of those a day. Then 20...30...etc etc.
trust me, after day 1, you'll feel your abs in pain. but...it works.
