But now I get it, and I'm starting to use it. This idea of "ambient awareness" of friends is a really powerful one, and to me it's what makes social networking sites like Facebook so powerful.
I think of it this way: I would never spend the time to call 200 people and tell them what I'm doing. For example, I spoke on a panel today, and I would never call anyone up to tell them about it. But instead, I sent a "Tweet" (that's what a Twitter message is called) from my phone announcing to the world that I would be at this panel today. That way, anyone who is following my "Tweets" can choose to attend if they wish. People who are "following" me on Twitter can quickly scan all of the Tweets I (and everyone else they're following) send and decide what they want to focus on. This is what I mean by "ambient awareness." It's like you know what 200 people are doing without having to talk to each and every one of them, and it's very powerful.
So give Facebook and Twitter a try, and see if you can create and receive some ambient awareness of your own. I imagine you'll really enjoy it and find it to be a very productive experience. My one caveat is that this takes time. You have to give yourself at least a few weeks and probably a few months of concerted effort to connect to people you know and start "following" them before you'll really see the value in it.