So, last night I got one of these bad boys



I didn't know what it was, but after a few moments of playing with it, it started to look like a calculator. Addition and subtraction I figured out quickly, but it seemed it could do more. I googled a bit and found this video http://www.youtube.com/watch?v=Bz8_tNDUDog

Original-Odhner, invented in the late 1800s, the one I got seems to be from 50s-60s, fully functional. I like it very much