Take a phone picture of your kids to show others in case they get lost. I've read so many techniques that one can use if their child gets lost, like taking a Sharpie and writing your phone number on their arm, or putting a business card in their pocket, and even putting their allergy information in their backpacks. BUT, what if someone asks you "What do they look like? What are they wearing?" If your child is lost, I'm pretty sure it would be hard to give such details at that moment in time. Taking a close up facial shot, and a full body shot of your child(ren) before leaving home when you're going out into very crowded areas is a simple thing that you can do to insure that if your child does get lost, you can show passersby exactly what the child is wearing and what s/he looks like.