I printed a few domos based on racing4micro's Domo Keychain, and a friend of mine suggested it would make a perfectly sized beer bottle opener!
There are 2 versions: One with a 6mm dia keychain hole and one without. Happy printing!
You can insert the coin into the socket while printing.
It's meant for a 18.50mm diameter, 1.4mm thick coin. I have included the original solidworks files if you need to edit!