Better yet, replace old technology with more energy efficient alternatives. If your employees can use--or even prefer--laptops versus desktop PCs, go for those, since they only sip at outlets. If you still have old CRT displays, replace those with LCDs for another big benefit.

Power can keep running when offYour devices have several states of "off," all of which use power differently. When your PC is sleeping, it uses less energy than if it were on, but it still draws more power than if it were fully off. You can make small savings by actually turning computers off.

Additionally, devices often still use a little power when they claim to be off. Battery chargers are the biggest culprits, taking electricity whenever plugged in. But most other hardware still draws a few watts when off. Turn off the power strip to completely stop this trickle.

Zack Stern is a freelance writer and editor based in San Francisco.