Electric Shoe

Popular Science:

Humans are not very efficient. When we walk, we waste close to 20 watts of energy per second. Instead of turning all calories into lift or forward motion, we turn most of them into heat that’s quickly dissipated. So my colleagues and I came up with a way to harvest the wasted energy from human motion and convert it into about 10 watts of electricity.

What would you do with a constant supply of a constant supply of electricity?