The night I started going out with my ex, I pulled the top off the beer we were sharing while saying the alphabet. It landed on his initial, so I thought that was pretty special. I saved it and made an earring out of it with some other found objects and copper wire. I started by making the tab into a charm by wrapping it with the wire and putting beads in the holes. I made loops at either end to attach danglies to the bottom and the hook to the top.
I made this up as I went along and just used what I had handy. I think you could have a lot of fun using pop tops as a base for beading and wire wrapping.