I heard about Seti@Home at the Sun SuperG meeting in Honnolulu in Hawaii. I was so impressed by the informative and funny presentation by Dan Werthimer that I decided to join.
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.