I learned a lot from this thread when I was planning our Thanksgiving 2006 trip so I just wanted to return the favor and pass on some of the tips I found the most useful:
1) Covering the stroller in case of rain. I used the rain cover that came with our stroller and it saved my DD4 from having to sit in a wet stroller when we came back from a ride to find that there had been an unexpected rain shower
2) Ponchos and flipflops for Kali River Rapids. Kept my DD and I dry (while our friends got wet because they thought we were silly to be wearing the ponchos

) and we just switched back to our sneakers when we got off the ride.
3) Riding in the back of the Magic Kingdom railroad. - My DD and her friend got to say "All Aboard" and got a little card that said that they were honorary conductors (or something like that....I don't remember the exact wording now)
4) Asking to ride in the front of the monorail. My DD really enjoyed it
5) Getting large bottles of milk and water from the resort gift shop for snack credits instead of the snack size ones in the resort convenience store or food court. This saved us a lot of money. We had brought cereal with us to eat breakfast in the room and these big bottles of milk were more than enough for us for more than one breakfast.
6) Putting all of the ADR's, parade/fireworks times, EMH days, etc on one index card and putting it in a ziploc to keep it dry. I found myself referring to the card all the time.
7) Tying a scarf or something noticeable on your stroller so that you'll recognize it. It's amazing how many blue strollers are out there
8) Take advantage of Photopass photographers. I got some great photos of my DD and I together (which is rare since, as a single mom, I'm usually the photographer)
HLDisney (who's tentatively thinking about planning a Thanksgiving 2007 trip......)