A professor at the University of Pennsylvania has developed a backpack that generates energy as the person wearing it walks. It recharges all of your electronic gizmos as you walk, and that could include an MP3 player or night vision goggles. It’s something the Pentagon bought into because of the benefit to soldiers. It comes at a very good time when people are discouraged about energy prices and the cost of gas and oil. People always seem to come up with innovative ideas exactly when we need them most. That’s the beauty of free enterprise.