Today computers are so powerfull that most of the time the processor is idle, and doing nothing, so it is a loss of resources. SETI @ Home is a good aim to make use in full of those lost resources. I suggest installing it and use it so from those lost resources we can help 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.