just back on 8/15/02. We didn't use a cooler in the parks, but brought backpacks full of snacks and juice boxes. Security looks in all containers, but didn't bat an eye at the food coming in (one of them commented to my niece "those peanut m&ms sure look good"). I did see a lot of coolers in the parks (mostly 6pk - 9k sized soft-sided coolers and backpack coolers, but I also saw a number of soft-sided coolers (probably about 15"x15"x15" in size) on wheels, similar to carry-on luggage (with retractable handles). At the magic kingdom, I even saw on guy pulling a large (probably 36-45qt) rigid plastic Igloo or Rubbermaid cooler on wheels with a handle so it pulled like a wagon. I didn't see any of these in the ride lines, so don't know what these people did with the coolers when they went on rides (maybe they had little ones so someone always sat out instead of going on rides). Oh, at a ride like Snow White's Scary Adventure, I may have seen one parked by the strollers...and on that ride, you get dropped off at the same place as where you enter. In any case, our experence at the 4 parks (entered a total of 6 times), there was never a problem bringing in food or drinks.