The National September 11th Memorial is releasing more free visitor passes online beginning today, and they're likely to go quickly.  The tickets were in high demand when the memorial's reservation system first launched on July 11th.  Five-thousand tickets were gone within an hour.  Passes for the memorial's September 12th opening and more information on the memorial can be found at 911memorial.org.

You can also visit the National 9-11 Memorial virtually via this video from Google Earth.