I would check out the book "protecting the gift" by Gavin... darn, I can't remember his last name. He talks about stranger danger and how it's not really something that should be taught like when we were kids. It's more important to help kids discover who and why they should be leery of, not to steer clear of all strangers. Oh, and if they get lost, they should try to find a woman/mother. He goes into further detail for the reasons, which I think are all competent valid and make a lot of sense.
Jen - SAHM to James
and my sweet baby Thomas