The design in Rhino was very straightforward. For the bodies of the keys I just used cylinders, tori, and a flattened sphere. For the names, I created the outlines in Illustrator and extruded them in Rhino. Put them all together, export an STL, upload it to Ponoko, and you're off to the races.
Well, a slow race, that is. It takes a bit of time for them to get printed, but it's worth it.