Today is 9/11, most of us will never forget the details of those days. I remember that I was off from school that day, and hearing something happened via the computer. I went to turn on the TV and I saw the first tower on fire, watching home footage of the tragedy happening over and over again. I also remember watching live footage of the second tower getting hit. Then the disaster of the second and then first tower falling. It was on TV, it just didn't look real - but it was.
The Internet slowed to a halt, web sites stalled, news sites didn't load, too much traffic to those sites. I communicated with friends and family via IM, since phones both analog and mobile were not working in NYC. And Google Systems reminds us of the Google Home page that aggregated some of the latest news.
The search community has started some threads on 9/11 today. Here are some threads I found right now.
I suspect other forums to start threads soon, Ill update this post as I see them. Also, Wikipedia has a comprehensive page on 9/11.
Update: Ask.com posted a major change to their homepage for the night of 9/11. The screen capture can be seen here, or you can just view the background image here.