I was flipping through the April issue of Field and Stream the other
day and noticed an article about a guy that had created a lure from a
beer bottle cap.
So, this morning I figured I'd give it a try and create my own.
I had a few Corona Light bottle caps lying around so I came up with
this:
http://www.flickr.com/photos/56301544@N00/10529829/
I took it out to the pond and, believe it or not, on my 3rd cast, I was
reeling in a small bass (probably about 1 lb, maybe a tad more).

Here's how I made mine.
I took the cap and drilled a hole on each end - one for the swivel hook
and one for the treble hook. I bent the cap and poured 3 BBs into it
and used a clamp to squeeze it tight so it wouldn't open back up. Then
just clipped the swivel hook and treble hooks on and I was done.
I used a light spinning rod and reel to cast.