I've been running SETI@home since the early days of the project. It keeps my systems doing something "useful" in their spare time. The project has really matured over time and the number of BOINC projects attest to the usefulness and popularity of this computing model.
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.
