-Victorinox Adventurer Swiss Army knife, or similar
-Verbatim Tuff n' Tiny USB flash drive
-angle grinder with metal cutting disc
-two part epoxy
Even though the circle part fits like a glove, you will need to remove other parts of the can opener. I ended up bolting an angle grinder down to a table with plumbers tape. There is probably a better way to do this if you have access to fancy tools. The angle grinder has a metal cutting disc that glides right through tool steel.
Make sure to keep checking the fit. You dont want to cut away too much material
When youre finished, you should still have the little finger nail hook to open the tool.
Sand the inside of the curve on what is left of the can opener.
Cut a slot into the key ring.
This helps give the epoxy more surface area and improves the bond.
You will also have to sand down the face of the USB key to get a good fit when the knife is folded shut. Sand on the side with the Verbatim logo so your USB contact points are still good.
Wait one day.
Remove the tape and use an exacto to trim away any excess epoxy.