I have seen a lot of cell-phone batteries before, but this particular one by Voltmaker recharges with something that is very easy to access: kinetic energy. The Voltmaker is very simple to use as you simply take it out and spin it like a nunchaku. It weighs about 10 ounces, and has a length of 6 inches, so it looks like it can fit in your back pocket. So even though … [Read more...] about Voltmaker allows you to charge your phone by spinning