1. Undoubtedly extraterrestrial life exists in one form or another and as the Monty Python song ends "I hope there is intellegent life somewhere in the universe because there is bugger all here".
2. We are already sending a beacon for others to find although I'm not sure if sentient beings elsewhere would consider most of the radio/TV programs a sign of life.
3. The entire concept of using cpu downtime for performing intensive calculations was brilliant. This is probably the most powerful parallel computing system in the world.
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.