In the name of trying out other social networking stuff (I'm using twitter reasonably frequently), and because I'm on the road and not yet accustomed to the time zone that I'm currently in, I've finally signed up for Facebook. After a few minutes of poking around, I just figured out how to link to my profile.
What's your favourite thing to do with Facebook? What makes it compelling for you?
Other than that, FB is just a linking tool.