An interesting side note (or, at least interesting to me) is that if you are a poor lass like me and can't afford the meal plan or a refillable mug (welcome to my pity party), you can purchase a paper cup with your meal.
The paper cup as the RFID chip in it. You can refill the cup three times and within one hour (or maybe it was two hours), whichever comes first. This cup transfers from resort to resort. We purchased and used one at AoA and then refilled it when we got back to POP.