When I was a teenager, we had a distinctly impolite name for a pull tab that had been removed from the can with the rivet ring still intact, said name being based on a persistent urban legend about the alleged redemption value of these relatively rare tabs. I can assure you, dear readers, that legend has nothing to do with the reason I am familiar with this handy trick for removing pull tabs with the ring intact every time. Turns out, a tab with an intact rivet ring is quite useful for mounting to wooden frames as a picture hanger. And I, you know, have to hang up lots of pictures. Seriously.