This multiuse portable cellphone charger is a third the size of conventional chargers and far more convenient. Simply put any ol’ AA battery into the aluminum canister, plug in your cellphone using the appropriate adapter (available for all phones except Sanyo and Audiovox), and a chip inside the device amps the battery’s 1.5 volts to a voltage powerful enough to charge and run the phone. A two-hour charge provides up to three hours of talk time. $25