We were at company golf outing. I remember getting a soda in the clubhouse before teeing off and seeing a scrolling report that a plane had hit one of the towers. I thought it meant like a Cessna or something like that. We were about to tee off and my manager came running towards us and screamed "THEY JUST BLEW UP THE PENTAGON. WE'RE AT WAR!" and made us all go back to work. I worked in a network operations center at the time and we monitored all the cell sites for the cell company as well as the WAN backbone. When the towers fell, it took out an OC-192 fiber ring that shut down communications for most of the north east, so we were tracking that down. The next day when they started showing the names of the victims on the screen on CNN, I guess they showed a last name that was the same as mine (I have a very unusual last name) and someone asked me if that was a relative of mine. A quick call to my sister confirmed that it was my cousin. I didn't really know him that well, but we very much looked alike, so it was sort of surreal.
Anyways, that's all. Sorry for the wall of text.