(Publisher: This technology has sooo much potential in the hands of imaginative youth that I will be updating this article for several weeks as a reference. The price of these 3D Printers have come down to as low as $2000. This means that mass production is about to be moved to individual home production of items using a free piece of software designed by,... anyone on the planet. You'll want to pay attention to this technology and start thinking about what it means. This information is just a taste. Watch for much more attention given this new technology.)
Demo 1 - "What You Can Make With a 3D Printer"
Demo 2 - Colors
Demo 3 - Unbelievable detail - The imagination soars
Wikipedia is always a good place to start for an overview about new innovations. Interested individuals supply the information and what is supported as true and relevant is retained (since anyone can edit what is said)
3D printers that can copy themselves are a theoretical aim that is being pursued. One such printer in development, named RepRap is released under the GNU-license and can print plastic parts. Research is underway that will let it print circuit boards as well as details in metal. The creator said about the printer that "We want to make sure that everything is open, not just the design and the software you control it with, but the entire tool-chain, from the ground up." The printer is capable of downloading upgrades of its design in order to create new and better versions of itself.