Why Seti?
I guess it has always been my belief that we cannot be alone in the Universe, Seti seems like a way that I can make a positive contribution to the search.
I think letting the rest of the universe know we are here has a very small risk attached. Any race who has the technology and can traverse the vast distances involved must be extremely advanced. One would hope that advancement and improvement go hand in hand, and that only a truly benign and curious race would be interested enough to come this far into a galaxy such as ours.....;-)
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.