While some people still use a normal calculator with AA batteries there are others that use solar powered calcs, and to make this case even better, there are other different kind of people that will start using water to make a calculator work.

ThinkGeek has added this new item today that includes a normal clock besides the calculator, they call it a Water Powered Desk Set and both devices work with water only. One refill is enough for 2 months of power, or so they say… Anyway, for $13 only this looks like a nice deal and makes you an environment friendly persona.

calculator, clock, water powered