I am Just learning of this technologie myself howerver if wish to learn more about this subject the best place I found so far is Reprap.org The cheapest kits I found were on Ebay
A video of this amazing machine printing a whistle
This is of course just an example of what it does there are many more videos available here The best part about this machine is that you can build it yourself and once you have one it is self replicating meaning you can use it to build another one