This is an amazing device: The RepRap (short for "Replicating Rapid-prototyper"), an open-source printer developed at the University of Bath. It was built using Linux, and all of the project's software and hardware components fall under the GNU General Public License. It's cheap to use, and can even replicate most of its own parts. Most of this article is an interview with the technical lead, plus there are links on the first page to videos and sample parts and objects made with the RepRap.