I've been bitten by the BOINC bug. I started off with SETI classic but never really got hooked. Now I'm BOINCing like crazy - 13 PC's at home (12 solely dedicated to crunching 24/7).
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.