My oldest daughter is about to turn 13, so I bought her an early birthday present. A T-Mobile Sidekick 4G. She thinks it's the greatest thing in the world and is absolutely thrilled to have it. I got it all hooked up with Google services. Contacts, email, maps, blah, blah, blah.....and Google Latitude, shared with my wife's and my Google account. (In other words, it's effectively a tracking device!)
Fathers from around the world can breathe a sigh of relief if they do this, and your daughters will thank you for it!. It's not that I don't trust her, it's just that.......well....if my dad had this tech when I was kid, man, I would have spent my life grounded and unable to sit down, that's for sure!