I really believe that this project would be a lot more popular if the credits could be used for anything... now I hear SETI is giving away t-shirts for all who donated more than 100$ - things like that should be available for SETI@home credits. Other than that, I like being a part of something like that...
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.
