Yesterday I had some stuff to do in the city and needed to have a few documents printed on the spot. It was then, at the printing shop, that the idea hit me. Would it be possible for 3D printing shops to appear? Say you want a complex device printed and you can't do it at home (or you don't own a printer). You go at the shop, get your stuff printed, pay and voila - you have what you needed in much the same way I had my paper documents the other day. Thoughts?