A few weeks ago, I had the pleasure (through a Canadian TV program) to learn of the Karakuri ningyō. Now, normally I would take no interest into dolls, but this is a BIG exception. It's a clever combination of science and the world of physics with the beautiful creativity and magic of Japanese culture. For more info, take a look at this wikipedia page:
My personal favorite is the Dashi karakuri, that was used to perform plays, myths,etc.