Call it what you will: phantom load, idle current, vampire power, wall wart; they're all euphemisms for the way devices use and waste electricity when they aren't even on, and they're everywhere. Here are some ways to save some bucks and carbon emissions and gain some peace of mind by eliminating unnecessary power use in your home.
1) Devices like the Kill-a-Watt and Wattson can point you to devices that attract the largest load, leading you to get...
2) A "smart" power strip like the Wattstopper Plug Load Control and Smart Strip Power Strip, that cut the power when your devices are off.
3) The Mini Power Minder has the smarts to shut off your computer’s peripherals and doodads when the computer itself is shut down.
4) Simply unplugging things like your cell phone charger, which is only in use a few minutes per day, will make a bigger difference than you'd think.
5) See How to Green Your Electricity to learn more about keeping phantoms, vampires and warts out of your electrical life.