Re: For your kids - would you?
The kit I got is made by a company called Kidz-iDz. They had reps at all of our local grocery stores and also had local police assurance that they cooperate with this company and approve of the idea.
As far as the GPS thing, the "harm" to the child would be putting them thru a surgery to implant the device - minor surgery but surgery nonetheless. And many people feel that its going overboard or a voilation of rights to be able to track location of a person this way. I quite disagree when it comes to children and their safety. But I live in NY which is more conservative than california and so its not offered here.