I don't share the views of those who moan and groan about Facebook eroding this, that and the other - and probably causing your mind to rot as well. If people spend hours a day on it, yes they should get a life, but a quick pop into it on occasion is good fun.
Facebook is particularly useful if, like me, you spend much of your working day alone. It gives a little sense of community as and when you want it.
But I've a real dilemma about how to use it. When I first went on Facebook, it was at the encouragement of the publicity person for a publisher. She saw it purely as another way to get exposure. 'Want to build up friends fast?' she said. 'Ask PR people. They'll be friends with anyone.' (Sorry, PR people, but it wasn't me who said it.) In that mode of operation, you accept friendship offers from anyone, because it's all about getting the biggest number of friends so you can use it as a PR vehicle.
But the problem with this approach is that the information you see about other people becomes increasingly meaningless, because it's about people you don't know. At the moment I can see pictures of my nephew's birthday party (you can't escape, Edward!), and little snippets of news and views from lots of people I know and like. Should that be sacrificed for exposure? I suppose the ideal would be if Facebook let you have two kinds of friends - the ones you communicate outwards to, and the ones whose stuff you will see. (Or does it already do this? I'm no Facebook expert.) But arguably this reduces the community nature of the beast.
Hmm. It's a tough one.