Sure it's a bit of a pricey publicity gimmick, but it's a cool one—and a wild example of fast-moving technological progress. What am I speaking of? Why, surely you've heard that Solid Concepts, the ...

The Liberator, for all the hoopla, was not really a gun. This 3D-printed firearm, on the other hand, is a gun. It is a copy of a 1911 made using public-domain plans and a laser sintering system that ...