I was probably not paying enough attention, but last winter, after we rented a car for three weeks and about $1300, we got a message from Cap One suggesting we use that 'charge eraser' to pay for it. By that time we had enough money charged to the card to handle this, and we did it. They don't charge an annual fee nor international currency exchange fees. And, even better from my point of view, they send me an email every time I use the card outside the US or if it is used for a large transaction (>$100). I bet other cards will start doing the same thing.