Scientists are closing in on a technology that would convert flowing blood into energy that could charge personal electronic devices.
Tiny zinc-oxide nanowires, some of which are only 1/5000 the diameter of a human hair, are able to produce an electrical current when subjected to low-frequency vibrations. These nanowires can be grown on most surfaces, including clothing, and the friction from pumping blood, body movements, or a gentle breeze would be enough to get them generating a significant amount of power.
Not only would this technology allow you to charge an iPod anywhere, but it is expected to enhance the capabilities of soldiers who are based away from traditional energy sources. As of yet, there is no timetable for its commercial production.