If you are getting calls from unknown persons and want to trace the location of call, then Phone Number Tracer is the best freeware application available. The Phone Number Tracer application allows you to find out the geographical location of any US or Canada phone number. Just type in any phone number and the application tell you which city, state, and country the phone is located in. It shows the details on the map as well.
It will give all the possible zip codes that are located in the area as well. It will come in handy whenever you need to learn the location of an unknown phone number. Want more? You can get the details of the person by making a payment to the service.
With this tool, you can easily trace out people calling you or even sometimes disturbing you.