Watches are able to power themselves by movement, so why can't cell phones be, too? I'd like to "invent" the same technology used in wind-up watches for our cell phones. We are so hooked to our smart phones, that most of us have to charge their cell phones daily. This daily energy could be saved just by taking every cell phone off their wall chargers. Our phones already have sensors in them, and we know that technology in pedometers have very sensitive sensors-- we move around a lot and our phones are always with us, so I think this could really work.