I got something 3D printed at work for a client once. It was pretty cool actually, they sold you boxes of 3D space, and anything you could cram into that 3D box, they would print out for you. The more you could fit in, the more you got for your money. We were designing an attachment to go on a JCB at the time, and the client wanted tiny models of it that he could attach to a Matchbox model of a JCB and demonstrate with, so I had to shrink down the CAD model we had and simplify it so that the resolution of the 3D printer wouldn't break anything. It turned out really well in the end - I still have one of the spare ones on my desk. I'll upload a picture if I can find one. EDIT: Found it