Here is a really quick post about another practical application of my 3D printer. I have an old Luminox watch that was missing the watch band retainer clip. Rather than trying to buy one, I simply printed a new one. I modeled the part from the same component on my new Luminox.
I measured all the dimensions with a digital caliper and made a drawing in Google Sketchup, exported to STL, and used ReplicatorG to create G-Code for my home-made CNC mill converted to 3D printer.
And here is the finished product.