An emerging set of mobile tracking applications have burst onto the scene since mid 2011. Here is another trial taking place in Western Australia targetting parents and children called the Myionu by AffinityOne.
If you are interested in some of our preliminary outcomes linked to parental tracking of children or the ethics of tracking and monitoring people using GPS-enabled devices you might like to follow up these papers:
Does tracking children necessarily make them safer? Is this really a way to help children develop a street-smart awareness? Wearable or luggable devices can be left behind giving parents a false sense of security. In addition, the security of such "up-to-the-second" data is a minefield.