I signed up to Facebook in 2007 (under my real name, not my blogging pseudonym) along with virtually everyone else I know. I go through periods of despising the damn thing, yet I still check in most days to see what people are up to. It is useful for staying in touch with friends and relatives, especially if they live far away or you just don't see them very often. For the most part my list of 'friends' is just that: people I genuinely know or am related to. My privacy settings are set to a level that ensures I cannot be found by anyone I don't want to find me - in particular I would not want to be accessible to work colleagues, for example. I cannot understand how some people have over 500 'friends': they are either spectacularly popular social butterflies or request the friendship of random people they meet in the street.
So in short, I'm a casual user who frequently finds it irritating but occasionally useful. I don't love it, but nor do I follow the line that it's doing the work of Satan. Ultimately it is a free-to-use application and people should be wary of how they use it and who they use it with. Just like anything else in this life.
Time magazine made Facebook founder and übergeek Mark Zuckerburg their 'Person Of The Year' for 2010 which was kind of ridiculous as, if he was ever to have been considered eligible for this award, it should have been a couple of years ago when Facebook was at the peak of its cultural significance. Nowadays I think most people are really rather indifferent to it. It's not going to go the same way as Friends Reunited (remember that?), but it's now a mundane part of the internet furniture. A coffee table, say. It's just there, doing what it does. No more, no less.
Twitter, on the other hand, is far more interesting.