See those connections, links and network graphs
If you like seeing how things are connected, you should check out some of TouchGraph's products. You can explore the connections between webpages, books on Amazon or even your friends on Facebook. Add the TouchGraph application to your FaceBook profile and you can see not only how you are connected to your friends but how they are connected to each other. I could easily see my high school group of friends, my college group, the GNOME group, etc. You can see which friends are hubs – The Tipping Point: How Little Things Can Make a Big Difference
If you want to play a real live "7 degrees to Kevin Bacon" game you can join the Columbia University Small World experiment. They give you a target, for example a housewife in Australia, and you have to see if you can reach her by forwarding the message through your friends.
