Not sure if this has been posted already. An hour-long street-level view of bystanders' reactions on that day. Interesting, and moving, for those of us who were not there.

http://www.vanadia.com/nycstories/my-911/story/

Also note 9:50 - 10:30, while WTC 1 is still burning, a startled reaction from the crowd, and movement north, away from the scene.

Following that, bystanders notice a fighter jet? flying near the scene.