Don't you wish saving the world was easy? Don't you wish you could just push a button and drastically reduce your energy consumption? Well, you can. One push of this Captain Planet-themed button activates special software which powers down as much of your PC as possible (without turning it off completely), drastically cutting the power consumption. (Even down to a tiny 1.8 Watts.)
The Eco Button plugs into a spare USB port, and the idea is that any time you leave your desk, one push of the glowing green button puts your PC into a deep sleep power saving mode. Once you come back from the short time you were gone (too short to justify shutting your system down, but too long to not feel guilty leaving it running), your PC wakes instantly and is ready for action without having to wait minutes for it to boot.
As a bonus, the Eco Button's software monitors exactly how much CO2 has been saved by the lower power state, as well as the cost. It also offers an added password security function, stopping roommates from using your computer while your away.
Available from FireBox.