I just came across yet another Memorial to 9/11 in Second Life, at the "Stagg International" sim (teleport link). They have created a beautiful monument to those lost on September 11, including the names of all those killed on a large marble wall. A waterfall nearby "depicts the tears of the world" and a rotating Earth symbolizes how much it affected the entire world. It's quite dignified and moving, reminiscent of the 2007 memorial in Second Life, that is still my favorite.
Organized memorial ceremonies will be held on 9/11 at 6:30am, 10:30am, 1:00pm, and 6:00pm PDT.
Teleport on over, read the names, say a prayer, and leave a 1 prim candle with a message. You will be glad that you did.