I was once told (but could not verify) thet there are still gambling cruise ships that will allow you to charge chips to you room, but let you cash your winnings in in cash. The story was someone charged $10k in chips to his room, didn't gamble, paid the room charges on credit card, cashed in the chips, and sent a bank check to the credit card company. An easy 10K miles.

But as I said, it was second hand, and I neither verified it nor tried anything similar.

Dave