Since humanity invented flash drives, these have been a really rich source of inspiration for designers and engineers. This regards to both manufacturers of USB drives and very creative concept designers. The latter seem to be eager to build USB drives into everything they see.
Wonchul Hwang, a very talented designers offers a new idea. The idea seems to be very logical: if you use your USB very often, if you keep it hooked to your computer most of the time, so why not to give an added value to your USB stick drive? The designer has combined USB drive with an AA battery. Thus Wonchul Hwang offers to use an USB drive for two aims simultaneously: to transmit information and to charge the accumulator. This simple, but genial concept is called AA USB.