I love buying refillable mugs. We fill ours up in the morning and bring them to the parks with us. We carry a backpack so we have room for them once they are rinsed out and placed in ziplock bags. Then, they are ready to use as soon as we return to the resort. The Value resorts, with their central Food Court are the best for refillable mugs. POFQ is also good for the same reason. The Epcot resorts are very inconvenient for mug use, as is OKW, CBR, CSR and PO-R. The monorail resorts and AKL are a bit better with their centralized mini food courts. Best of all, I get to drink out of a variety of Disney mugs once I get home!