I work in a related area, which is why the idea occurred to me. To combine the two would be awesome, but is a long-term prospect.

One more point. You mentioned BOINC. I believe BOINC sends all input data to the client with each request. In other words, it's only good for computationally intensive tasks (lots of computation per unit of data). The same is true of GPGPU. That's why I brought up "average" as an example: it's a commonplace function that is not computionally intensive at all. The work is almost entirely in finding the data and accessing it.

What I really want to know, though, is who else has thought about using BitTorrent for this kind of thing, and what they think.