Originally Posted by Brander
The application "Latitude" lets you add contacts or friends to your latitude contacts. Using GPS, it lets you view on a Google map, where that phone is located using the Cellphone signal. You can view the map in satellite view, or plain map view to know the location of the person you are trying to find. Hope that helps!
Provided that they (your contacts) share their locations with you. So if this app is installed on your son's phone, he/you should enable the sharing option with you, and preferably the "best available location" option.