Ok, back from my trip and here are my thoughts:
1. Athletic Sandals: Teva Tirras and Kamik Mustiques
Crocs wedges .. . not so much. Kids Keens and Crocs

2. Body Glide: Lost it after the first day. No one other than me got any blisters and I just got one minor one so I'd call this unnecessary if you're using athletic sandals and dress shorts
3. Sundresses in the park:

4. Dress Shorts: The cheap cotton ones I got on
Amazon (keeping in mind that the hottest it got on our trip was 93)

, the Jockey skimmies are going back because I don't like the feel of nylons and that's what they felt like. I almost didn't wear anything because my dresses were knee length and I thought that they'd be fine. I wore the cotton ones anyway and got a nice gust that blew my skirt up so I'd say they were necessary.
5. Packing Cubes: For a spring time Florida vacay with only one pair of long sleeves and pants,

, our typical trips to Wisconsin during the winter, probably wholly and completely useless because each bag would only hold one sweater or a pair or two of jeans. Kinda defeats the purpose.
6. Trading Pins were a bust, the kids didn't really get into it and there didn't seem to be a lot of CMs with pins.
7. I followed a recommendation and cut the Frogg Toggs smaller. DD7 really liked having them but they grew a lovely pink mold so I'm really done with them.
8. O2Cool misters:

for keeping the kids cool and entertained. They were kind of heavy by the time you add the battery and water though. And there was much fighting about who got what color since they were a random mix. They did survive 4 foot high drop tests about 50 times during the course of the trip so they're surprisingly durable given that they're just foam and plastic.
9. Glow items:

They were a hit on the Poly beach and my kids made some new friends by giving them away. They were also helpful in keeping track of each other in the dark.
10. Custom Autograph books: Cute and fun but also kind of heavy and led to upset over seeing or not seeing characters. Overall, I was happy I did them (and got several compliments and questions about them) but probably won't do them again unless the kids really want me to. They took a lot of time.
11. Items to trade with the Jawas:

They were the most awesome character interactions we had (sorry, Chewie, you're a close second). My DS3 kept going back over and over trying to retrade what they'd given him. We had to pull him away to give others a chance (there were 3 Jawas in the Cantina at the time so at least he wasn't completely monopolizing them). They liked the slightly broken metal slinkies and gave DS a nice Mickey pin in return. They were happy with the metallic looking heart bracelet and mardi gras beads too.
The only thing I regretted not buying were the collapsible water bottles. Those would have been really handy. I decided we could use the dining plan mugs to bring along water in the parks. They were not water tight enough to just throw in the bottom of the stroller and weren't insolated enough to keep the water cool so they were kind of a pain.
All and all, most of the things I got were pretty useful so thank you, lovely folks on the DIS Boards! I hope everyone else has been enjoying their purchases and that they've been handy on your trips.
