There are lots of situations where we wish we could keep a better eye on the whereabouts of certain people in our lives. We may have elderly parents that still have their driving license but may have medical concerns or memory problems. We may allow our teenage children to borrow the car over the weekend, but can be certain that they are truthful about where they are going. Then there are all those in a relationship that are suspicious that partners may be cheating. So what can we...