Productive Product: Solar power worked pretty well for calculators in the 1980s, and now it's available in cell phones  from China's Hi-Tech Wealth company. Like any other new technology, this does not come cheap: think about the $500 range and for now it's only available in China. But it's a great way to show off your green-friendliness to friends and colleagues without having to invest in a hybrid car, and the extra talk time is very useful. Several new models are due out soon, hopefully coming to Western shores. Explained on Hi-Tech's site , "A 1.3 mpx camera and an MP3 player are fairly standard additions to cell phones these days, but the solar panels do make this guy stand out. The panels trickle-charge the battery in any amount of light, including indoors (or even by candlelight), and the battery life is 2.5 times longer than it would be without the panels. An hour of direct sunlight will give users 40 extra minutes of talk time."