If you tend to zone out and leave your computer on to suck energy needlessly, Local Cooling (download it from CNET Download.com) helps you tell your Windows XP beast when to rest, giving the electric company a break, too. I've been using this free download on two PCs for a couple of weeks. It lets you time automatic snoozes or shutdowns for precise periods of neglect (also see Earth2Tech). Use Vista? Check out this battery saver.
By bringing hidden details about consumption to the surface, Local Cooling encourages you to relax your energy usage with little effort. Otherwise those controls are buried pretty deeply within Windows or Mac system folders. But Local Cooling sits on your desktop, calm and translucent, showing the true power hunger of your CPU, monitor, and graphics card.
Then it quietly adds up how many kilowatt hours and trees you might be saving. By last count, I've spared 0.362 of our leafy friends (is that like saving the bark or a pile of branches?). Since using Local Cooling, I haven't noticed my CPU or monitor napping any more than they already were before, although that could be because I tend to turn off the screen when I take a break.
You can log in to your Local Cooling account from any browser to see results from your stable of machines, and check out what other users are saving. The widget's maker, Uniblue Labs, calculates that using 15 computers leads to about as many globe-warming carbon emissions as one car on the road.
Green social networks for cleaning up your carbon footprint include Make Me Sustainable (more here) and Yahoo Green (more here). In addition to providing smart, power-saving tools for socializing, computing, and even hosting your Web site lately, people are dreaming up computer hardware that's green out of the box. The novel Zonbu rental PC is energy-efficient, while this regular-looking Dell notebook is the first to win an EPEAT gold rating for sustainable design.