Mark Healey (from Valve?) is developing Rag Doll kung foo. A fighting game which is basically an extreme rag doll physics demo. You control your fighter with your mouse, which you use to flail your limbs at your opponent. Check out the trailer. It's supposed to be coming out this summer from Valve and will be made available on their Steam service. There's even a multiplayer side to the game where you will probably be able to rag doll it to the death.