Once, we've (me and my friend) decided to build reprap printer just for fun and for simple and quick prototyping. We've got it! But it needs more tuning, at least in my opinion...
Using skeinforge (so sloooow :-( not multithreaded, maybe slic3r will be solution in the future)
Built RepRap Prusa with linear bearings, nothing exotical.
Wanna something know? Don't be shy, ask me!
Happy and successful printing