Here’s a unique way to earn some miles on a Carnival cruise thanks to FlyerTalk. Basically you can load up your casino “card” with up to $1,000/day (per guest), and you can charge it to your credit card. Then you can cash out whenever you want to. The only thing to keep in mind is that you could end up with a LOT of cash, and also that you have to declare over $10,000 in cash at customs.
I would definitely do this if taking a Carnival cruise. It’s much easier than the dollar coins sceme, in my opinion.