I run Seti instead of Folding or something else because I think the medical industry gets plenty of funding, so while folding proteins is worthwhile, I'd prefer to help find something that proves we're not alone out here in the great open spaces.
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.