Boinc (
http://boinc.berkeley.edu/) is wonderful software for distributed computing. Question: why isn't there a Bitcoin-like currency that is mined via Boinc? Gridcoin almost did this, except there they give you a bonus to your ordinary search-for-hashes-with-your-GPU mining, rather than just awarding coins based on Boinc solutions. Why not just tie it directly to Boinc, and dispense with the crypto mining altogether? (Ripple's almost doing that, but it's just a temporary promotion.)
I think there's a desire for proof-of-work based coins that use a different proof-of-work -- i.e., not SHA-256 or scrypt -- which has been part of the success of Primecoin. Also, finding prime numbers is vaguely useful. But Boinc is useful in a much more concrete way, plus anyone can get it running because the client is easy to use...
