My DD (9 and 6) go to sailing school in Annapolis, MD, for a week each summer. My DH is from Maryland and is from a family of sailers/boaters. My FIL bought the girls a Coleman fanny pack toa carry lunch/sunscreen/sunglasses...that is awesome. You can see it here.
http://store.colemancampingstore.com/coforkideh2o.html
Last night while I was organizing the stuff we are bringing to WDW, I discovered that the fan/misters we have fit in the water bottle section of the Coleman fanny pack! We bought the larger size fan/bottle with the wide opening for ice at Walgreens (half price now) so I was shocked, actually pleasantly surprised, that it fit! The pack itself is quite roomy--I think it will fit DD9's digital camera, a suncreen stick, snack, small refillable water bottle, autograph book, sharpie pen(in a ziplock, of course) in additon to the fan mister

which we are hoping cuts down on our load!! We don't want to feel like pack mules!
The fanny pack has a handle/strap so it can be carried by hand easily.
I am hoping that we can distribute the load so the bags stay light (ie taking one sunscreen stick for all). HOWEVER, we will leave lots of room in DH backpack just in case the kids get cranky!!!
For the record, I tried on the packs and they are quite comfortable!
Hope this helps!