WhereMyFriends is an interesting mashup that will show the geographic location of your Facebook friends on a Google Map. You simply connect your Facebook Account with WhereMyFriends and the app, within a minute or two, will fetch the location of all your Facebook friends and puts them on a map.
You can hover or click on any of the pins on the Google map to see the names of all friends who are in that particular location.
There’s one downside though. When you create a Google Map of your Facebook friends, it is public by default and there’s no way to change this setting. That mean others can also view your friends list and their respective locations like in this example.
WhereMyFriends will help you visualize the geographic location of your friends as mentioned in their Facebook profile. However, if you would like to see where they are based on their Facebook check-ins, check out Nearby Friends – another neat app that display your friends' recent Facebook Places check-ins on a Google Map.