This is the first model I've ever made and posted on Thingiverse.

I wanted a basic solution to keep my Raspberry Pi attached to my Printrbot Simple because I use it as a print server. These are basic, thin mounting brackets that use the two Z axis bolts on the right side of the printer to mount. The Pi simply slips snugly into the brackets. 2 of this STL will need to be printed (both sides are exactly the same).
The case I'm using on my Pi is approximately 31.6mm thick, so that's what will fit in the mounts in my file with no modification.

Since I am not very good at 3D modeling yet, it would be nice to see others improve on this design to make it much better.