Last year, I made the mistake of writing my kids' names and phone number on their backpacks in permanent marker. When they wanted/needed new ones all the information was still on them. So, this year I made backpack tags for each of them. On the back of the tag it has all their personal information. I love that these can be moved from bag to bag each year.
To make them, I used a baseball card holder. They are thick and very durable. I found these at Walmart. Then I scrabooked a cute front and back and printed off the personal information and pasted it onto the back of the tag. Then punched a hole and added the metal ring. It was really quick and easy.