On a different scientific front, I remember reading in a newspaper or magazine recently that a college scientist has developed a backpack that harnesses the linear (up and down) motion of walking to generate electricity... The backpack was designed to experiment with possible ways to eliminate the need to carry spare batteries for PDAs, cell phones, CD players etc.
The conclusion was that to provide the energy to run a CD player, a person could carry spare batteries or in the case of this new device, carry a candy bar to provide the energy to generate the power themselves... It concluded by saying that it was easier to carry a candy bar than spare batteries.
They just missed a couple of little points in the article. First, candy bars melt... Second, in order to generate the power from that one candy bar to power the CD player, the backpack generator weighs 40 pounds.