My husband is always amazed that I can tell where he is. For the most part, I just know him so well and so it is not very difficult to predict where he will go or what he will do. Also, I have a little trick up my sleeve. My husband has an iPhone, but he doesn't use it for much more than talking on the phone, sending emails and playing games. He doesn't know how to track iPhone, but I do. Basically, I know where he is almost all of the time. Maybe some time I will tell him about this.
The Phat Photographer