When I took my sis and her kids to WDW a few year ago I had the same idea as you. I wanted to give them something each week for a month before we went. I ended up with 12 things a piece. Here they are and you can make them over to fit your needs.
Toothbrushes....the drugstores here sell Mickey toothbrushes, I bought a permanent pen and wrote each of their names on them. Hey even the adults would love this.
Disney shampoo and soap....I had saved up from previous trips, you could post here and maybe someone could send you some to help you out. You give each family a little bottle of Mickeys shampoo to help with the wait.
I also gave them disposable cameras, autograph books, hats and water bottles from our local DS, disney pins, sunglasses, oh and here are a few more....
Disney playing cards.....my local discount drug store sells these for a couple bucks. They are adorable. They can then bring them on the cruise.
I watched the
disney store for beanies on sale.....our store had a Mic holding a Menorrah (sp? sorry) and we live in an area where these did not sell, they marked them down to 1.00 each. With the snip of one thread the Mics had nothing in their hands at all.....what a deal. You could send one per family if you find something like this.
Here is one I think would work great if you have all adults and/or families going
Buy the Pioneer albums 12x12 on sale at Joanns ( 7.49 when the run the sale) First send them their album with an title page....i.e."Our family reunion aboard the Wonder" Next month send a second page decorated with cruise borders and headers, keep it simple, do them all the same, if they have never scrapped put a journaling box on each page you send. With instructions to insert it into the next page protector.....by the time you go they will have a beautiful photo album all ready and waiting for the those special pics. And you will have been a big part of it. What a great family memory.
well hope these help you a bit
cindy