I discovered an (unfortunally not so mutch popular - just ~27000 users) interesting power saving utility:
[quote=“LocalCooling.com”]…it automatically optimizes your PC’s power consumption by using a more effective power save mode. You will be able to see your savings in real-time translated to more evironmental terms such as how many trees and gallons of oil you have saved.
Local Cooling will:
* Cut your energy bills. * Reduce the amount of Greenhouse Gas CO2 emissions as a result of your reduced PC power consumption. * Give you full control over your power mode settings. * Improve your overall computing experience and efficiency. * Show you in detail how much you have saved since installing the software.
Our goal is to introduce 100,000,000 PC users into the Local Cooling community. If just 100 million of us optimize the efficiency of our computers’ energy consumption, we could prevent over 300 billion kg of CO2 gas emissions, equivalent to over 1.8 billion gallons of oil, in just the first year alone.[/quote]
I already asked them to release the source code under a GPL-compatible license.