That thing is amazing. Part of me is amazed by the craftsmanship and ingenuity, and part of thinks "this guy has WAY to much time on his hands".
This is the one that amazes me the most. I saw this several years ago at Concourso Italiano and heard it run. It had me giggling like an idiot it was so cool.
http://www.youtube.com/watch?v=ncsaUNEzaTw
I showed this to my wife and her first comment was "That's incrdible!" and her second comment was "He's probably not married."
Cheers,
Kurt O. (Who still has dozens of unbuilt model kits in storage)