If you have a small child, these are great to put in an emergency kit with a picture of your family on one side, and contact information on the other. In the event of a disaster (hurricane, earthquake, act of terrorism, tsunami, volcano, radiation leak, meteor strike, mega-tornado, rogue comet, nuclear war, government coup, solar flare, doomsday virus, civil unrest, alien attack, economic collapse, super nova, second coming, 12/21/12 apocalypse, zombies, etc.), just put it around the child's neck so if you get separated, anyone who finds the child will know how to help reunite you. It might be a good idea to include contact info for a friend or family member in a different geographic area, so they can help coordinate finding one another from an area that's not affected. I have something like this that I made out of laminated plastic in my hurricane kit, but I'm going to replace it with one of these "dog tags". You do have an emergency kit, don't you?
Come to think of it, a couple of years ago my wife and I were at the Bronx Zoo, and we saw a small boy, probably 4 years old, running back and fourth and crying. When we asked him if he was okay, he said he was lost and couldn't find his dad. Luckily, he knew his own phone number, so we called it and his mom answered. She called the father's cell and organized a place for us to meet. The father was very happy and thankful. Had the kid not known the phone number, a tag like this could have saved the day. So, even if you're just going to a crowded public place, a tag like this is a great idea on a small child. Incidentally, the mother called us back later in the day to thank us, and went way overboard telling us what an idiot her ex-husband was for letting it happen. Every parent knows how quickly a child can disappear, even if you look away for only a second.
