Is Bitcoin really the only way to make using your computer's power? Folding @ Home is sorta like it, but it's a charity thing with no profit(I guess you can count pride though). Has anyone seen something like Bitcoin mining before?
Distributed computing is not limited to Folding.
There are dozens of other interesting projects out there
http://boinc.berkeley.edu/But well, except bitcoin and distributed computing i think that no, there isn't anything you can crunch on your computer.