If you want to check the actual physical location of your facebook friends, then you can use any one of the following Facebook apps to locate your friends on Google maps.
Map Motive automatically parses the profiles of your friends on Facebook and plots them on a Google Map. Obviously, if a few of your paranoid friends have kept their information private on their profile, they won’t be displayed on the Google Map.
Each friend plotted on Google Map contains a thumbnail of her profile pic, her latest status update and other most useful information about her. You can use Friend Finder to locate a particular friend on Facebook by her name.
If you are traveling, you can quickly zoom this Google Map to find out all your friends around that location. You can also decide a meeting place with one or more of your Facebook friends around a place and put a marker on the this Google Map to point that place.
Go to Map Motive.
Like Map Motive, this Facebook App also gets all the info from your friends profiles and plots their locations on a Google Map.
Once you install this application, you’ll see a Google Map that displays the current location of your Facebook Friends.
Along with Google Map, it displays a number of tables that helps you sort your friends on Map based on their sex (male or female), political views (conservatives, liberal etc.), relationship status (single or committed), birthday month etc.
This sorting capability of this app based on a particular criteria may be very useful. For instance, if you are single, then you can quickly find out other single people, that share your interests.
Go to SocialMine