Except over 2% of the worlds population is on Facebook and there's a whole lot more of that over there from my experience. Like you said, I could give a shit what people had for lunch and although maybe it's my friends, a bunch of people who know each other chatting becomes just that. Lunch and dumb Star Trek movie references. And we all know which has more housewives who barely use the net talking about packing up the kids for soccer. I still think FB is a great service (and has helped me rediscover old friends), just too much like a new AOL for regular use for me. But they're changing, including looking more Twitter-like and opening up to alternative clients shortly. We'll see.
The two services of course aren't the exact same experience or direct competition, but Twitter easily gives you options to follow (which works much better than "friending" though FB wins on finding) interesting people. For instance read Mark Polansky getting ready for a shuttle launch @ Mark Polansky (Astro_127) on Twitter.
Anyway, I'm getting fed up with FB, so resurrecting this thread. As I don't really have enough time for both, and since some of their functionality overlaps, I'm using Tw more and FB less recently. Should humanflyz or anyone else want to post their username I'll follow. I'm blessingx, for general info, and blessingflix (just split), for film & related.