1. Use computer and monitor power management. Doing so can save nearly half a ton of CO2 and more than $60 a year in energy costs.
2. Don’t use a screen saver. Screen savers are not necessary on modern monitors and studies show they actually consume more energy than allowing the monitor to dim when it’s not in use.
3. Buying a new computer? Make energy efficiency a priority while shopping for your PC and monitor. Look for the ENERGY STAR label or browse the Climate Savers Computing product catalog.
4. Turn down the brightness setting on your monitor. The brightest setting on a monitor consumes twice the power used by the dimmest setting.
5. Turn off peripherals such as printers, scanners and speakers when not in use.
6. Fight phantom power; plug all your electronics into one power strip and turn the strip off when you are finished using your computer. When feasible, we also recommend unplugging the power strip from the wall to avoid high voltage surges which may occur during an electrical storm.
7. Use a laptop instead of a desktop. Laptops typically consume less power than desktops.
8. Close unused applications and turn off your monitor when you’re not using it.
9. Use a power meter to find out how much energy your computer actually consumes and to calculate your actual savings.
10. Establish multiple power schemes to address different usage models. For example, you can create a power scheme for playing music CDs that shuts off your hard drive and monitor immediately, but never puts your system into standby mode.

The above tips and more great information can be found at http://www.climatesaverscomputing.org/learn/saving-energy-at-home/

You can also get more involved by pledging to reduce your computer energy consumption. I did.