Monoff (May 28, 2009)
Monoff will save the world! Ok that's probably an exaggeration, but it can save a bunch of energy by turning off your computer monitors. Put it on your desktop, click it, and your monitors will turn off. Move your mouse or hit a key and they'll come back on.
You can also make it turn off your monitors after a certain amount of time by adding a commandline parameter. For example, if you want it to turn off your monitors in 60 seconds, you'd run it like this:
monoff -delay=60
Don't worry if you have no idea what the commandline stuff means, just click the monoff icon and your monitors will turn off and the world will be saved.
If you need more control over delays before your monitors turn off you might want to check out Sleeper.