Whenever I think of 9/11, I always think of the comedian David Cross. He is one of the best comedians around, but you might know him as the flamboyant Tobias from the brilliant Arrested Development. (Which was cancelled because it couldnt compete with quality television such as Ugly Betty and dancing with the stars. Its hard to type sarcastic tones) It sheds some comedic light on a tragic subject and he really points out the bullshit that people pulled after 9/11 (AKA the week that football stopped)
It's from his CD "Shut up you fucking baby". Have a listen.

www.youtube.com/watch?v=g5tldEQg6is

Here's some other dark comedy that has nothing to do with anything, but it makes me laugh.

http://www.youtube.com/watch?v=kHmvkRoEowc