I have been playing with personal computers since ... they exist !
Such a processing power worldwide is just a total waste of energy if its not used for something.
Thoughts about SETI and SETI@home
SETI is a great programme, although should I be totally convinced that there is no reason life should not exist somewhere else in the universe, the probability for identifying a signal by a random search is very very very very very very very very low.
Anyway if we don't try, for sure we won't find.
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.