You can use a CC (through PayPal) to add money to a Kiva account. You can then lend out the money, in $25 increments, to people in developing countries, so that they can start/expand their own businesses and increase their income, and they give you back the money in monthly payments, which you can get back using Paypal. You can earn miles, and help people improve their standards of living, at the same time. IMHO a lot more meaningful than buying big sacks of coins from the mint.