It's funny, I had a similar experience taking a nap in the office. I listen to the home of the spinny hard drives all around me, and suddenly my mind zoomed out, and I became aware of how many computers there were around me, and try to imagine how many there were in a 10-mile radius.

That radius kept expanding and I became painfully aware that most of them were just sitting there, not doing anything useful at all.

Not a very original idea — I was familiar with SETI@Home — but it was weird to me how little it had caught on.

Most computers are just spinning their wheels most of the time. That's a lot of power just sitting there.