I've been playing with a 3d printer lately, specifically a Solidoodle machine that deposits ABS plastic filament. As part of a larger project I've been designing various mechanical parts, challenging myself to do without support structures and keeping manual finishing steps to a minimum. One of the things I've tried to make is an entirely printed, functional screw thread, for both male and female parts. The result is the nut and bolt combination documented here.
As for the larger project, I'll publish more about that here soon, so keep visiting!