The WH's near me have added a type of ATM machine in the store. One of those where you swipe your card, enter your PIN and get a receipt back. You then take the receipt to the cashier to pay for your meal. The machine says purchase required, it didn't say how much the transaction fee is and the people there didn't know either.
Good idea I guess, I don't know how many times I've seen people scrambling for cash to pay their bill.