This is is a simple, 3D-printable (caveat: It requires some springs, bearings, rubber bands, and nuts/bolts), fully-mechanical computer. It has 3, single-digit base-10 counters for memory, and processes a chain of 10-position punch cards. With the included program, it will compute the first few digits of the fibonacci sequence. It is effectively an entirely mechanical reimplementation my FIBIAC project (http://www.thingiverse.com/thing:22803)
See it in action here: http://www.youtube.com/watch?v=1lMTgYoIGvo
And a full write-up here:http://www.chrisfenton.com/the-turbo-entabulator/
Take that Babbage!