Instructables user elha2 had problems when shopping for an energy-conserving power strip, and writes:

We bought some “Energy Saver” power strips from Zweibrueder. The devices are very solid and not very expensive. They feature an external switch and no further intelligence. You can place the switch in a good spot and leave the cabling under your desk. The major drawback when using those power strips with manual on/off switches on PCs, is that you’ll have to wait for your PC to shutdown completely before pushing the off switch.

Check out the neat mod to use USB power as a signal to turn the power strip completely off once the PC shuts down.