I try not to carry a large amount of cash when I travel. First of all, the danger of theft is greater in certain foreign countries; second, ATM’s are now widely available and the currency exchange rate is better from bank to bank than at currency exchange terminals in airports or cities. In addition, because credit cards supply a detailed chronicle of expenses on your bill, it makes it easy to calculate how much you have spent. Another advantage, of course, is that you don’t have to pay the bill immediately..