Damn, I feel ancient. Most of you were in school or too young to remember? I was in college! 
... 
I was walking back to my dorm from my early morning class when the first plane hit -- I ran into a friend on the sidewalk, she told me what had happened, and it sounded so absurd I almost didn't believe it. After the second plane hit, class was canceled for the rest of the day. We had a lot of students and professors from NYC and DC -- most of them were panicking because they were trying to call their friends and families and couldn't get through for hours (my college set up a phone bank and information center in one of the school buildings to try to help).
Yay, someone the same age as me! (I was feeling old reading most of those too!) I was in my first week of first-year university. I was just about ready to leave for school in the morning (about 7:30am my time, I think) and I went to get my dad, so we could head out. He was watching tv and said hey, check it out, some really horrible pilot hit the WTC. I come in and there's the first plane smoking away. We sit and watch the news for a minute or so and then the second plane hits the other tower. We were both like... wtf, did the second pilot get distracted by the first accident, or is there some weird weather condition, like high wind, or what? Nobody knew what was going on at the time. We watched for a few minutes and then left for the day.
When I got to school, I signed onto a computer and logged in to a browser game I was playing at the time, and started chatting with the Americans. (I'm Canadian) The first tower had fallen sometime on the way to school, and as I was talking to them, the second one fell. One of the guys I was chatting with was in a New York apartment building a few blocks away and could see the entire thing, and was telling us what was going on. I remember we were all stunned and rather somber discussing the day's events up to that point. There was a lot of profanity. (which was normally censored on this site, but the admins let it go that day) I remember one guy swearing up and down that once they found out who was responsible, he was going to enlist and go kick the # out of whoever was responsible. (we didn't know who yet) Another guy just completely lost it and was ranting about how glad he was that this had all happened. (!) Of course, this pissed off everyone else, so he got illegally killed a bunch of times for his horribly insensitive comments.
The first class I had that day was classical history. I remember because, without any preamble, my professor immediately launched into a monologue about Middle Eastern history and relations (this was 2 hours or so after the planes hit, and we knew by then that the prime suspect was al-Qaeda and bin Laden, but it wasn't confirmed) instead of whatever the day's topic was supposed to be.
The other class I remember was my introductory civil engineering class (I have an electrical engineering degree) and the prof spent the whole class telling us 'exactly how the towers fell' even though it had only happened about 7-8 hours previous and obviously nobody had any of the details yet about any of that.
Then I remember that evening being glued to the tv news. I remember my little sister coming in, and she couldn't understand why I was so transfixed with what was going on; I guess she was too young to really care yet.
I had a real shock the next morning, though. I'm an avid reader, and I had suddenly remembered one of Nostradamus's quatrains. Now, his stuff was pretty vague, but one of them was thought to talk about a war beginning in New York City, as the quatrain mentioned something like 'the city with two names twice' or whatever. (New York City, New York) Now -that- really made me wonder... I have read since that that might've been an aprocryphal anecdote, but if it was, it was one that had been around since I was a kid at least, because I read about it when I was very young. (i.e. like in the 80s/90s, before 9/11)
