I run SETI@home because I believe in helping out in projects, and this is a great way for me to do it, and with a server on 24/7 that noone ever really uses besides me, its a great way to help it keep a purpose.
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.