DARPA is working on a project that will convert energy from the human body to power a variety of military gadgets. From the article: "Obviously, our bodies generate heat — thermal energy. They also produce vibrations when we move — kinetic energy. Both forms of energy can be converted into electricity. Anantha Chandrakasan, an MIT electrical engineering professor, who is working on the problem with a former student named Yogesh Ramadass, says the challenge is to harvest adequate amounts of power from the body and then efficiently direct it to the device that needs it." If I remember the movie correctly, this didn't turn out so well for the humans.