Nvidia is on a roll for the past couple of years, they can do no wrong. The most recent achievement was the acquisition of Ageia, the makers of Physx .

Let me explain PhysX, or better still, lets read the wiki-page:  PhysX can refer either to a proprietary realtime physics engine middleware SDK developed by AGEIA (formerly known as the NovodeX SDK) or their PPU expansion card designed to accelerate that SDK. Only games that use the PhysX SDK can benefit from the presence of a PhysX card.Middleware physics engines allow game developers to avoid writing their own code to handle the complex physics interactions possible in modern games. Sony has licensed the PhysX SDK for their PlayStation 3 video game console. The PhysX engine and SDK is freely available for Windows and Linux systems, but hardware acceleration only currently works on Windows. 

Nvidia CEO Jen-Hsun Huang says Nvidia is working to add PhysX support to its GeForce 8 series graphics processors using its CUDA general-purpose GPU (GPGPU) application programming interface. PhysX support will be available to all GeForce 8 owners via a simple software download, allowing those users to accelerate games that use the PhysX API without the need for any extra hardware. (Older cards aren’t CUDA-compatible and therefore won’t gain PhysX support.) With Havok FX shelved, the move may finally popularize hardware-accelerated physics processing in games.”lets hope this collaboration benefits gamers, without a major increase in price.