No degrees of separation?

I recently got spammed invited to participate in Karl Bubyan's Six Degrees of Separation application in Facebook. This application navigates the 'social graph' in Facebook, offering a couple of tools to allow the user to test the ' Six degrees of separation' hypothesis. The application and its interface seem quite slick - and it has the now obligatory visualisation (reproduced here). There's an irony here. The six degrees of separation idea can only work if there is some barrier to being directly connected to someone else. In the real world, where relationships are subtle, complex and often not immediately apparent, the game of trying to trace the connections and counting the 'hops' from one person to another to reach the 'target' person can be diverting. On Facebook, at least so far, there is only one way in which users can be connected, and that is through the 'friendship' model. In such a simple model, the degrees of separation between any two users are relatively easy to calculate. Although a user can be several degrees of separation removed from another, the barrier to them becoming directly connected is very low - all they need do is become Facebook friends. And how many Facebook users have turned down a request for 'friendship'....? So, I suggest that for any actual person in whom you are interested, Facebook presents two degrees of separation:

• infinitely separated (the other person does not have a user account on Facebook at all)
• a separation of zero (you are Facebook friends)

Will these global 'social-software' tools such as Facebook gradually make the 'degrees of separation' notion irrelevant? Still, this tool is quite interesting in terms of what it allows the user to discover about their relationship to other, named, users, before the user immediately renders it irrelevant by 'befriending' them! And it's surely interesting that, within the population of Facebook users who have installed this application (4.2 million at the time of writing), the average number of degrees of separation is, wait for it...... 6.12!