At my university we have a Makerbot Thing-O-Matic which has been aptly named "Madre" ("Mother", in spanish) because it will print the necessary parts to build a second generation of 3D printers (several Prusa-Mendel printers).

I decided to create a small sign that we could place on the printer. I printed the letters separately from the background, in different colors. The background has the shape of the letters indented so that they can be fitted inside. I was amazed by how well it turned out, but obviously few people (if any) can benefit from the files to print this specific sign, so I have written a tutorial explaining how to make your own design using Inkscape and Openscad.

mrgroup.dyndns.org/mrgroup/doku.php?id=3dprinting:home

I hope you find it useful!