I was lucky to have arrived in my home city at about 6am that morning starting a scheduled 15hr layover. If I had been on any other trip I would have been stuck away from home until the airspace system reopened instead of watching it all unfold with my wife and 1yr old son.
I had gone to bed and was listening to the radio to go to sleep. When they said that a second plane hit the towers I got up. I stayed up most of the day even though I had ben up since mid-afternoon the previous day.