https://onlycoin.com/?referral=AlpNrIUG
Another idea I had that is now reality.
I was actually thinking of all of the price club cards, but this might actually serve.
The only question I have is, if you select the card you intend to use by hitting a button, then give it to the waiter, and he accidentally touches the button, would it change to the wrong card?
Oh, and can it become a shopper club card?
I will have to look deeper into this. I love the idea.