My friends do this: one kid has a speech delay and trouble communicating, and the other has severe allergies. They make an XS slim kind that fits kids. My friends include their own info/phone number and description of the conditions.
This timing is funny - RoadID just posted a review on FB by the mother of a kid who was dropped off at the wrong place by the bus. The child had a road ID w/ moms contact info, thankfully.
It seems like giving possibly creepers the child's name and address seems like a bad idea. Just my opinion though. Is there an option that isn't as visible as the wrist?
A friend bought these for my kids this year as a Xmas gift, it just has their first name and "please call my mom and dad if I am lost. They're probably dealing out". Along with our phone numbers. We really haven't used them yet but I thought it would be good for field trips and when we go to Disney