Fivedollar saw a 3-D printer demonstrated last February, did some homework, and purchased stock in several companies that directly or indirectly are involved in this technology. Such printers utilize a variety of materials, not just paper. When the price drops to the point of mass-market appeal, it will be interesting to see what develops. It could be the biggest thing since the tablet PC/iPad or just a gee-whiz, nerd gizmo. Caution: I am not recommending that you guys go out and invest in these companies. Some of them are trading at quite a premium to their sales. Do your homework. In my case, I jumped in, but only with very small positions.

mmmm, what if we used an electron beam melting 3d printer using titanium powder instead of plastic. From wiki: "Electron beam melting (EBM) is a similar type of additive manufacturing technology for metal parts (e.g. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum. Unlike metal sintering techniques that operate below melting point, EBM parts are fully dense, void-free, and very strong." NEMO already has made a full(mostlly) titanium .308 you can see here so there's the pattern.
http://nemoarms.com/worlds-titanium-ar-3...

This technology will only grow and grow rapidly. If they can control the grain structure and molecular bond arrangement of steel. They will be printing hardened steel. That could eliminate CNC machining and create a whole new industry.

When I print out my Liberator, it's going to be neon pink! :D
http://cubify.com/cube/