Just saw these new betas circulating around the net today. It's Beta 185.20 and they have a new option in the NV Control Panel called "Ambient Occlusion"? Haven't a clue what this does but below is a comparison with it tuned on and off in Crysis. Some are reporting profile issues if you use them. I don't so my systems running so well at the moment I think I'll screw it up by trying these. Download is slow as hell.
Ambient occlusion is a shading method used in 3D computer graphics which helps add realism to local reflection models by taking into account attenuation of light due to occlusion. Ambient Occlusion attempts to approximate the way light radiates in real life, especially off of what is normally considered non-reflective surfaces. For example, in the way light through a small crack in the curtain in an otherwise darkened hotel room can slightly illuminate the entire room, and not just the path of light passing through the crack itself.
Ambient Occlusion - Off
Ambient Occlusion - On