Not sure anyone's done this one before...
So I've got a thing for vintage bells. I think every bike should have one. When I'm amongst pedestrians on a path, it's a lot friendlier than yelling out "on your left". Out in the countryside, someone's riding the opposite direction, I give 'em a ring. When I'm riding with one of my friends with a bell, if we're not together, I ring it. If I hear a ring back, all is good.
Bells are cool.
More of my bells (with sounds!)
here