H2O

Florida water tastes different to me.  And according to a message board on Disney, disboards.com, that I frequent, others agree with me as well.  Anyone with babies on formula, you will want to buy a gallon or two of filtered water just for bottles because your baby will not be used to it.  We also buy bottles of water as it is much more expensive in the parks.  We dump a little out of a couple bottles of water each night and put them in the freezer.  Then right before we head out to the parks, we take the bottles out and put them in our day bags.  By the time we want to drink them they are usually almost already defrosted but still cold.  One of our strollers has a freezer bag (Baby Jogger) that has worked wonders and we didn't need to freeze bottles.  But that's an additional "bag" security needs to check at each park which can be a hassle.