I happened to be walking in the area and saw the signs for the Memorial and thought I'd wander over and take a look - I didn't have my good camera with me, just my carry-everywhere (a Panasonic TS2). I'd heard that the Memorial wasn't very impressive, but the more I looked at it and saw what it was trying to say, the more moving it became. It was especially moving to see the "bench" for the youngest of the victims, who was born in 1998 and would have been 3 years old, plus a 9 year old sibling and probably their father.

If you want to know more, take a look at the official site:

http://www.pentagonmemorial.net/renew/

It explains something I noticed - most of them are set so that the open end faces the building, but a number face the other way. They are done this way to differentiate between those who died on the hijacked plane (which have the opening facing the building) and those who died in the building (which have the open end away from the building).