Three-dimensional printing (or additive manufacturing, or rapid prototyping) is of course a fairly nascent technology that nonetheless holds great promise. While private companies like Makerbot, Stratasys, and even Hewlett-Packard have pushed the boundaries of the technology by developing less-expensive and more accessible printing systems to more people, the industry on the whole hasn't really benefitted from a huge injection of investment or a meaningful mandate from a body like the DoD--one that, when it puts its mind and money to something, can actually enable technological leaps forward.