When it's cloudy outside and the solar-powered charger isn't going to cut it, the Epiphany onE Puck power-saving charger will save the day.
Not only is it a great way to save money on the energy bill, it also doesn't need to be charged by any power sources that people don't have control over (a.k.a. the sun). Two different temperature-gauging sides make it easy to use this device as a coaster, allowing it to harness the heat or coldness of the beverage and turn it into power. Place a hot drink on the red side or a cold drink on the blue side, plug a cellphone in the USB port and it almost magically starts charging.
All you need as a power-saving charger is the Epiphany onE Puck and a drink!