I was sound asleep (maybe I could get a job at the FBI; they were asleep on 9/11 too). Wife had gotten job in new city and went on ahead of me, I was still in my hometown packing to move. Got woken up by phone call from her telling me to turn on the TV. TV was packed... Got on the computer, news sites were all slammed and dialup ISP was going slow as fuck (small town, rural Alaska prior to them getting cable modems) so I couldn't see anything. Finally found a site that would load. Not very interesting all in all.
My brother's story was slightly more interesting than that. He was at NASA Langley doing engineering at the time and when they went to Threatcon Charlie, he decided to un-ass the base before they went to Delta and all of the traffic on and off was stopped. Another relative worked for one of Alaska's senators, and saw the smoke pouring out of the Pentagon on his way in to work. He pulled over and called the office, asked if there was any point to coming in? Nope, boss is "elsewhere" right now, go home.