Here's a nifty gadget that may eventually save you a few bucks: the Outlet Regulator from Conor Klein. The device was built around the concept of severing the flow of energy to a rechargeable device while it's still plugged into a wall outlet.
Previous devices have accomplished this task by incorporating a toggle switch, requiring the user to manually sever the electrical connection once the device has fully charged. However, the Outlet Regulator does something entirely different: it releases the charging cord without the need for user intervention.
"Once the plug falls out, all energy consumption stops and only resumes once the plug is inserted again," Conor Klein said.
Klein also added that the Outlet Regulator uses a timer circuit and electromechanics to eject its plug.