I was at work when someone came into the office to tell us about the first plane. We thought it was a tourist Cessna. Then one of the IT guys working from home called about the second plane and we knew it wasn't an accident. The internet froze on all the news sites - BBC, Sky, CNN etc so we couldn't get any info from there. Actually IIRC the only site that seemed to be working was Janes, and I remember mentioning OBL and AQ to my work buddies, who hadn't heard of them!
So the day passed with not much work getting done and a running commentary from the IT guy phoning in from home every half hour.
Then sometime in the afternoon 'they' decided it might be a good idea to evacuate the tall buildings in Manchester city centre, so we were let out and I went home to watch the news well into the night.
I was expecting a response like the cruise missile strike in 1998 or a Special Forces op to take out OBL as I couldn't see the US nuking Afghanistan, or even selected targets. I can't believe we're still there 9 years later. Having said that though, Tony Blair was on the radio this evening discussing his new book, and suggested it may take a generation at least until the ideology that started this conflict is diluted enough to reason and negotiate with.