Wild Things: YA Grown-Up discussion

I'm looking for books that deal with strangers and being lost. I'm trying to talk to my four years olds about stranger danger and what to do if they ever get lost. I feel like reading would be a great transition to talking about it. So does anyone have any great book titles dealing with these topics?

This list has a few. I remember the Berenstain Bears one being pretty good.

http://www.goodreads.com/list/show/79...