Afinia/Up-Printable Strandbeest
After some tweaking of GolanHertz's original model (converted to STL's by cyclone) I've arrived at a version of this which is assemble-able and reasonably robust.
My motivations were to honor the genius of Theo Jansen http://en.wikipedia.org/wiki/Theo_Jansen and to disprove cyclone's assertion that the model is unprintable :)
It's never going to walk very well due to the floppiness of the crankpins (see the last photo) but the mechanism does work, it was a good printing challenge, and the end result is a great sculpture.
See the "Instructions" tab for details.