I do feel that it is extremely probable that extraterrestrial life exists somewhere in the universe, justified by nothing more than the law of coincidence. Whether it is intelligent, communicates or expresses itself in the way we expect it to, or even has form and definition in our sense of "life" is another question altogether.
Radio signals are a good place to start. It's properties naturally lend itself to being a choice of interstellar transmission by any intelligent form.
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.
