Maybe you have read about the Water Powered Clock. Now someone has taken the same kind of technology and put it inside a calculator.
Never be without batteries again. Our scientifically engineered calculator is ingeniously powered by water. Just pour the water into the rear power pack, insert the stopper panel and the electrolytes in the water generate all the power needed to function. Perfectly safe and environmentally friendly. The calculator has a large LCD screen and standard functions.
The Water Powered Calculator ($9) is available from Bits And Pieces.