I got into SETI@Home because of a boyfriend of mine in middle school. :) He was really into computers and space, and SETI@Home was perfect for him when his CPU was idle. My original name/ID was under his team. I thought (and still do) that it would be really interesting to find life elsewhere in the universe, and really cool if my snippet of analyzed data turned out to be the discovery of a lifetime. SETI isn't just about aliens--the data can be used to discover other things about space, and it's like exploring space from my living room. :)
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.