Digital clocks use so little energy -- I have an Oregon Scientific alarm clock/thermometer combo, and it ran on a single AAA battery for about 2 - 5 years. (at least 2, but maybe as much as 5) One day I might just take it to work and measure it with a 6 1/2 digit DMM. So very low power gadgets can indeed run on 'funny' sources, but you'd need quite a few of them to charge Li-ion batteries. -- Wacky Races 2012!
