Raspberry Pi cases are a dime a dozen, but we all know making your own is usually the best way to go. The recently released Model B+ changes the form factor of the Pi enough that old cases don’t work. Thankfully, Imgur user quantumCity shares a B+ case made from a Manila folder.
The case here is pretty simple, but fits the B+ snugly and doesn't look too bad considering it's made of paper. All you need to do is print the PDF, cut it out, then fold it up. That's it.