The New York Times article 3-D Printing Spurs Is Spurring a Manufacturing Revolution covers the growing impact of this technology.
The article contains a nice, non-technical description of 3D printing:
A 3-D printer, which has nothing to do with paper printers, creates an object by stacking one layer of material — typically plastic or metal — on top of another, much the same way a pastry chef makes baklava with sheets of phyllo dough.
3D printers have been around for years, but until fairly recently they were expensive and used almost exclusively for product design and rapid prototyping.
But their prices have fallen substantially over the last few years and low end professional 3D printers cost less than $5,000. Hobbyist 3D printers are even cheaper. As the article points out, Makerbot sells a hobbyist version for under $1,000.
The price drops, coupled with improved "sprayable" resins, plastics and other materials, has resulted in 3D printing machines moving beyond prototyping to use in final product manufacturing. The NY Times article covers a number of examples.
The growth of 3D printing is part of a broader trend towards small manufacturing. This trend is covered in more detail in the Intuit Future of Small Business research brief Today's Hobbyists are Tomorrow's Hobbypreneurs.
We also cover 3D printing and the trend towards small manufacturing in The New Artisan Economy research report.