Okay, so you wouldn't use this to get to the office, but I thought it was so cool I had to share!
The twin-engine, fixed-wing Lazair airframe was designed by the University of Cambridge’s Paul Roberton and Flylight Airsports‘ Paul Dewhurst. The electric plane is propelled by ultralight 10kW peak brushless electric motors powered by 12 Lithium Polymer cells. The motors power the carbon fibre propellers which make the plane fly. Dr. Robertson designed a battery management system that allowed him to monitor the energy and temperature of the cells. This was required to maintain balance between capacity and lifetime.