Shake-U-Lator Calculator
by Collin Dunn, Corvallis, OR, USA on 11.10.05
Yes, we know that there are lots of calculators that run on the glorious power of the sun, and at least one to which you just add water. While we are generally unflinching in our support of solar-powered gizmos, we also like innovative, alternative energy solutions to solving problems. Enter the Shake-U-Lator Calculator. With 20-25 shakes, you've got a good 10 minutes or so of calculating power and a fun little exercise to boot. Employing Faraday’s Principle of Electromagnetic Energy, you can see the energy creation in action though the visible chamber as the magnet slides through the copper coil. They're available here for £9.99. Via ::Gizmodo
Two other options. Abacus and/or the human brain. If you get an abacus for the blind you don't even need to have light to see it. Get real skilled at it and some can do it all in their heads. Of course the calculator is very very fast but sometimes the time spent hunting for the darn thing could be surpassed by the ability to do the math all in your head. Mental math is great but sometimes things like this calculator can help society a lot as well. Are there any stores in the US that sell it?
This one actually seems anti-treehuggerish. Chances are most people already have a cheap battery powered calculator lying around, and replacing a battery is probably less environmentally harmful than buying a new model. Not to mention the proliferation of solar-powered calculators. No shaking, no batteries. An considerably less expensive.