I think this is a great idea. I'd love to get a "stamp" and add marks to coins -- with the owner's approval. But even better, I think a specific "chop" coin could be made. Here's my idea: Make a coin that looks like a meat cleaver. and since they usually have a hole in the upper corner, you could use that to attach a tag. Then people could add their "chop" to you tag and not your coin, if you so choose. Anyway, if any of you artistic types out there want to sketch that up, feel free. Or if you feel it's a flop, don't bother.