After cracking open a Nintendo Famicon game I noticed that the internal dimensions are the exact same as the RPi. The ethernet port was a little too tall so I had to cut that section out, but after putting a base plate you can barely tell.
(Disclosure, you can totally tell but I still love it, also electric tape is temporary)
http://imgur.com/a/oA1Ag - Album
Anyone else have any cool homemade cases?