Solar Chargers - http://www.youtube.com/watch?v=z0nhDclQH5M - Solar Charger for iPhone 4, Smartphones, MP3 Players, iPhone/iPod, GPS devices etc...
Solar Charger for Various Devices
Have you ever experienced the hassle of having no battery for your cellphone while you are outside and far from home or any electrical outlet? You can avoid such problem with solar chargers. There are some that only cost only $130.