Not to crowd gamer's / renderer's, but the price/performance ratio of fragment processors is grabbing attention of some who have no interest in graphics. There is a site for General-Purpose Computation Using Graphics Hardware, http://www.gpgpu.org/
. There you can find people, mostly researchers, doing many different kinds of systems, and Universities building Supercomputers out of video cards. NVIDIA has come up with a new language, CUDA, http://developer.nvidia.com/object/cuda.html
which eliminates the need to fake out the cards by passing large amounts of data disguised as textures, and buiding an image to return that is not really an image.
I didn't really answer your question, but the domain of my application is finance / investing.