It has to be said, although there are loads of Facebook applications around, very few actually seem to do something with the underlying social data, which to some extent is the most interesting aspect of the social networking phenomenon – especially if you’re in marketing.

For a while I’ve had one, Friend Wheel, sitting on my profile, that simply puts all your Facebook friends as points around the edge of a circle, and then connects together any of your friends that know each other. It produces a pretty pleasing effect, as you can see from the picture, but from the point of view of looking at how your friends connect with each other, it’s not overly clear. What is actually needed is a more fluid way to position your contacts.

There are two other applications that do that. The first, TouchGraph actually runs almost separate from Facebook, but using data from Facebook to do some clever things. I’ll talk about that in a bit. However, the other is called Connection Cloud and is intended to sit within your profile.

The second image pictured was created using Connection Cloud from my connections on Facebook. It’s a lot easier to see what’s going on in one of the larger versions – the colours indicate the sex of the person represented, red for female, blue for male and black if the information isn’t on Facebook. It’s pretty easy to spot where Beth is on the graph, as she is the red dot in the centre that connects together a lot of the other contacts. Below that is a big pile of connections which represent part of Beth’s family, so are all interconnected to each other. Interestingly there are also a couple of floating contacts, or groups, who are generally work contacts – the algorithm that produces the graph will place these groups and singles further from the centre. What the graph clearly shows though is that there are certain key contacts that link distinct groups together, but also that there are distinct groups of friends. If you look at this blog posting by the author of the application you’ll see that his social graph has two very distinct major groups, with little connection between the two.

Moving on, I passed over TouchGraph – but that’s mainly because it does rather a lot more. The basic concept is similar to Connection Cloud – indeed the author of Connection Cloud admits that he wanted to write something to put the cloud idea in TouchGraph into his profile. Where TouchGraph goes further is that it includes network information – so if you’re in a city network it will link in to that – and also works on photographs. What that means is that if you are tagged in a picture, it will find that too, indeed will track on from links in the pictures to find other people. It does all of that in a fluid constantly changing diagram that expands as you click through the links. It’s maybe not as interesting if you’ve got limited pictures, or if like me the pictures are elsewhere, but for visualising how your contacts connect it’s a really great little application.

What is worthwhile remembering as you click through is that TouchGraph is not doing anything much more than retrieving information from peoples Facebook profiles, and if you’ll forgive the pun, joining the dots. When you factor in that if you’ve filled out a lot of the interests questions, Facebook applications can retrieve that too, you can quickly see quite what a powerful tool the whole social graph that Facebook is building up can be to marketing departments.