I remember the first time that I realized that you could find out information about somebody if you knew their cell phone number.  I used to think that in order to find out a cell number you would have had to know something about them.  While that is still true, much of what you may need to know about a person can be found by using reverse cell look up. If you have their cell number then you could find almost anything you want to know about them including their address and other things if you are willing to pay a small fee.