Screwless Icosahedron Gears
This was based on Eccentric Sphere Gears (http://www.thingiverse.com/thing:6499). I modified the SCAD files so that it would use pins instead of screws to secure the gears to the center piece and instead of a sphere a icosahedron is used. Also, this one is not eccentric so that the gears spin without the object dramatically changing shape. The STL files are already plated for printing (it can be done in 3 prints).
All individual pieces are now available (all sans 'ichedron') - for single prints. Thank you Andychn for noting the importance of including those.
Note the reason for the different colors in the picture are due to running out of the green plastic mid-print and having to insert white filament in it's place (by feeding it into the extruder as the green filament was fully consumed).