I lived in Athens, GA at the time and was working at a pottery studio near downtown. I was driving to work when the DJ broke in on the college radio station I was listening to to say that a plane had just hit one of the towers. I didn't think much of it, other than, "oh, the poor people in that building".
I got to the studio and started rolling out clay when the owner who lived across the street came over and told us "you guys need to see this". All 7 of us gathered around her TV when all of a sudden, the second plane came into view. The news anchor said "oh shit" just as the second plane hit. That's when the stunning feeling hit us all that it was definitely not an accident. Most of us started crying. My sister lived just north of NYC and her boyfriend had interned at the Windows on the World restaurant (he was still in culinary school at the CIA) so I tried to call them, but couldn't get through (finally did later on - both were fine and not in the city that day, thank goodness). Needless to say, nobody got much work done that day.
I didn't have a television at home, so we went over after work to watch the news. That's when I learned about the Pentagon and the other plane. Then I remember how eerie it was to hear no airplanes. I also remember a couple of weeks later when the planes started flying again. Also eerie.
I moved to NYC in 2006.