A Folding@Home beta client for CUDA-Enabled nVidia GPU cards is available.
http://foldingforum.org/viewtopic.php?f=43&t=3186
I'm not sure, but from what I've read, this setup seems FAST... REALLY FAST... EVEN FASTER THAN PS3?
Here's a list of supported cards...
http://www.nvidia.com/object/cuda_learn_products.html
...so my 6200 doesn't qualify
Since I don't have a newer nVidia card, I can't test this out right now. But wow, something like this could really shake up the rankings!