Want to lower your electric bill? Replace your standard-issue charger with AT&T’s new Zero model ($12, att.com). It shuts itself off once any USB-powered device is fully charged, prolonging the life of the battery and avoiding so-called phantom power usage—which occurs when gadgets burn electricity when they are finished charging or even turned off. (The average household spends $100 annually on unnecessary power, according to the U.S. Department of Energy.) Plus, the charger is compatible with nearly all non-AT&T phones and other devices, such as iPods and Bluetooth headsets. So you’ll never have to worry about having the wrong cord on hand when you’re out of juice.