Hi! I haven't read through the whole thread but I'm sure the basics have been covered. I was trying to think of things we take that may have not been mentioned:
-stroller fans with extra batteries (very nice-definetly worth the $$)
-benadryl spoons (DS5 will break out in hives if even a drop of sunscreen gets on his face or ears + the excitement of WDW = awesome use of benadryl spoons)
-parachute men, you can get a big bag, especially around Halloween time, from Target for $5. Everyone likes parachute men, good thing for waiting in lines and small enough to carry around
When you go with a stroller, especially a double stroller, it is really easy to overpack.
In 2 days I will embark on my 1st solo parks trip! B/c I won't have the stroller I got a Vera Bradley mini-hipster to take with me and I was impressed with what I could reasonably fit inside: chapstick, cell phone, 2 AA batteries, camera, flip camera, money, nail file, small umbrella, hand lotion, small pad of paper and a pen.
So you really can take as little or as much as you want into the parks-I have to admit I am very guilty of overpacking our park bag!