Software to set up my own Seti-style project?

Greetings,

Are there packages that allow a person to set up their own "Seti
style" project? For example, I have access to a reasonable number PCs
at various sites, and it would be rather nice to have them humming
along working on some computationally intensive problems I have while
they are idle. I am wondering if there are any tools out there that
would help me set up something like Seti (on a much smaller scale of
course). I suppose I might ask for volunteers too (friends and family
probably but clearly this would be a relatively small scale
enterprise compared to Seti - maybe 100 or so machines in total.

Thanks!
Ted