Indiana University Keychain Bottle Opener
This is just a combination of the tapered bottle opener by br3ttb (http://www.thingiverse.com/thing:12348) and the IU Logo by quasiben (http://www.thingiverse.com/thing:6052).
I printed it off using wood filament and I get tons of comments on it. Handy to have on your keychain and doesn't take up a ton of space on your keyring.
Note: For best results, insert your penny mid-print after it's done printing the walls for the opening and before it prints the roof. At least on my Printrbot, the roof tends to sag and then it's a real pain to try to get the penny in there after the print is complete. Just be careful not to burn your hand while you're trying to get it in there!