Comment Re:More than just graphics (Score 1) 175
If you have a compatible nVidia graphics card (anything within the last 3 years), you should look into CUDA (http://www.nvidia.com/object/cuda_get.html). It's got a steep learning curve at first, but it's quite awesome. OpenCL is another option designed to be more cross-platform. Either way, you basically write some code in C (well...C with a few extensions and limitations) and it executes in parallel on the GPU.
The current batch of nVidia GPUs support floats with both single precision and double precision, although there is a significant performance penalty with double precision for most applications. With the announcement nVidia made today, though, there will soon be new cards with much less of a performance penalty for double precision.