The purpose of the RepRap project is to produce a 3D printer that can effectively reproduce itself. Fears of robot domination aside, this is a truly momentous project. However, it's a difficult task to conceive of the most efficient machine design - the fewer and simpler parts required by the design means it's easier to reproduce. Therefore, the RepRap designs have gradually been simplified.
Today we're reading a report by Josef Prusa, a Czech student, who's working on the RepRap design. He was "able to reduce parts count, assembly time, use of vitamins and also price" through the use of very creative design.
Specifically, he's designed bushings and a greatly simplified X-axis that are of course, printable. Well done, Josef!
An interesting observation here is that at least in the case of the bushing, Josef was "inspired" by other work. We must all remember that such inspiration cannot occur unless designs are transparent through open source principles.