I've been trying to figure out the best way to come up with the smallest possible custom case for fitting a Teensy 2.0 board, a bluetooth module that is about the same size, and a few bits of additional circuitry. Poking around with google to see other projects, every time I see something I really like, it looks like it was produced with a 3D printer. Are there any other really nifty ways to manufacture one-of custom cases out there?
I made the case for my initial prototype out of cardboard and paper mache, which was time consuming and fun, but I can't say the result looks really spectacular :-).
I think you deserve some kind of prize for "Most Absurd Arduino Case"
Looking at your method I would have suggested starting with a block of foam as a placeholder for where the Arduino would be, then applying the paper mache (or clay, or automotive body filler, or fiberglass/epoxy) on top of that. Once the shell is cured the foam can be removed afterwards either by scraping it out or using a solvent like acetone (but that's a lot messier).
Or you actually have it 3D printed. Have a look at 123dapp.com . Its a software by Autocad that lets you output files for 3D printing or lasercutting and let you order them directly from their inhouse service. And its quite cheap as well.
The software is quite easy to use (maybe you are familiar with autodesk inventor allready) and you can design pretty much what you want.
By the way, I finished another prototype (using a Teensy board and a JY-MCU bluetooth module this time), and it is as different as night and day, but still kinda silly:
