Do I think extraterrestrial life exists? Yes.
When and How Humans will discover it? By accident. I mean think about it, would you want to encounter the human race right now.
If we do transmit a beacon the message should be "Is it true The Hitch Hikers Guide to The Galaxy refers to our planet as a two word entry, mostly harmless?
Imagine if we got a response. "YES".
I run Seti at home beacause it is the coolest thing to do with your processor since gaming. It's also a lot more peaceful even though a lot of it is number "crunching".
I do hope you guys start getting data from Radio Scopes in the Southern Hemisphere. That would be very cool indeed.
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.