This year, the talk in online discussions, at conferences and among the nerdosphere is all about 3-D printing.

One of the fascinating aspects of this technology is that it is so diverse. There are open-source products, like 3-D printers that cost as little as $650 from MakerBot, based in the Brooklyn. And there are high-end 3-D printer options from companies like Dimension Printing, which begin at around $20,000. And there is 3-D printing on demand, offered by companies like Shapeways.