we found on AMAZON.com, these water proof necklace wallets. They fit money, credit cards, and my cell phone in there. We needed them for our trip to Sea World last year. They work great at SDC because it's just right there around your neck, see thru, and water proof. Another idea we had was to make demographic laminated cards for my autistic son and two year old daughter. We laminated them and used safety pins to secure them to the back of their shirts. Just in case they some how got lossed in the mix, all of our information and who they were was easy to find out. Again, waterprof and in easy viewing.