I would bet if you look behind your desk you have at least one power strip back there providing power for things like your PC, your monitor, speakers, and maybe several other things. I would also bet that most of those devices aren't used when your computer is turned off, yet they remain running most of the time. An interesting power strip called the PowerUSB Basic has turned up that has four AC outlets and will turn off anything connected to three of those outlets when your computer is turned off.
The one outlet that isn't programmable to turn things off is for the PC. The power strip connects to your computer using a USB port and has a USB cable that is 6 feet long. The idea is that you use those three outlets to plug in your printer, monitor, speakers, or other things and then when you select shutdown on your computer, the USB cable will tell the power strip to turn all those other devices off to save electricity and be greener.
Another interesting option with this particular power strip is that it can be set up to turn things on based on specific events. That means you can do things like have the printer only power up when something needs to be printed. I wonder if you can have your speakers only power on when there's audio that needs to be played. The PowerUSB Basic is available now for $69.99.