During wartime cities were told to turn down the lights and what does New York do? It sets up the brightest lights in the country, a beacon that could be seen from 20 miles away! It was, at once, a defiant gesture and spiritual recognition of the lives lost. And we will remember.
On March 11, 2002 apparently New York had thirty days of lights in the place of the towers. Some pictures and the above paragraph can be found here.