At last a green solution to all of those calculators that run on gas. Think about it. No more carbon monoxide fatalities during math class. No more having to take your calculator to the mechanic to get an emmisions check. At last, we can cleanly crunch numbers.
So I exaggerated a little. This water powered calculator is still cool. It uses three water batteries for power which have two electrodes inside made from a special alloy. When immersed in water they produce electricity through a chemical reaction.
Just refill the batteries as the water evaporates, every 2 to 3 months. Only $11.