In my Facebook profile I have added my ‘friends wheel‘.
It creates a picture of all your contacts and the links between your contacts.

There are different views to play with, so you can focus on different aspects of your circle of friends. Such as different geographic subsets (networks), the overlap between you and a contact, or a random selection of contacts from your list.

From the default result two things in my Wheel catch the eye:

One is the concentration of connections at the bottom. The names there are the people that I have been in touch with a lot in the past years in the blogosphere. No surprises there. They apparantly form the center of sorts of my on-line connections.

The other interesting part is the sparsely linked section on the right. This indeed are people I have met recently in a random fashion, or stem from entirely different contexts than the usual blogospheric circles (e.g. one is a fellow boardmember from a fraternity 16yrs ago that reappeared on my radar a month ago).

Nice visualization of contacts. Also because there is a more interactive flash version as well. The Facebook app has been created by Thomas Fletcher.