I've found flickr to be a great site to promote my images (art, not photos in my case) and there are many groups, but a search left me with little 9-11 sites or groups, and yet I think this is a lively thread I started that I feel am holding my own (albeit an atheist group- no offense to those religiously inclined):

My point is flickr's a great free outlet with massive reach, on par with Myspace. Join in, promote 9-11 truth causes.