NVIDIA GPUs have CUDA support so they have their own PHYSX just with a PHYSX card the physics are improved so they are more realistic and i think the card reduces the framerate on some games. Unreal Tournament 3 being one of them
Not really well not at the momment anyway but soon a lot of games will have PHYSX support so i dunno you can get one if you want but it seems a lot of money for something that you wouldn't really use
