Funny John, I had a similar thought once. (Of course, I was sober at the time :) It's cows. I suppose any ruminant would do, but my experience happened to be with cows.

The force of a belch from a bloated cow is enough to blow a baseball cap off of a human head. This could surely be used to power turbines. The methane produced is a terrific natural heating fuel that burns at roughly 200 HPU's (that's hamsters per..) and the projectiles that usually accompany this intestinal outestinal dry very quickly, and to a consistency that would make them perfect for filling in potholes in the street. So you have power, heat, and transportation problems solved. I know people who know math, and this could work.

Now, John, have a cuppa coffee, eh?