as long as you are on site, you can put a credit card "down" at check in. Your key to the world (disney speak for room key) than allows you charging almost everywhere. Almost anywhere with the parks , water parks and resorts take this. There are some independant non-disney own places in DTD that you will need cash or a cc for as well as on the boardwalk. Otherwise, I carry about $20 a day in Disney and with the exception of tips to resort valets, I usually don't spend any cash. A single drink, mickey bar, popcorn, etc. can be charged to the room