Just curious if anyone has tried one of those new pre-paid Mastercards. I saw some on display at a CVS store...from the fine print, it appeared you could use another credit card to 'fund' the pre-paid card. The obvious mileage earning opportunities would be very intriguing: using the pre-paid card to get its value returned in cash from an ATM to pay off the card used for 'funding', which earned the miles on the funding transaction (ie, use an Amex Starwood card to charge $500 at a time to fund the pre-paid MC, and then use the pre-paid MC at an ATM to get the cash to pay the Amex).