Tim Kreider, my favorite cartoonist of pretty much all time, has this to say in re: 9/11 on the New York Times Happy Days Blog:
I like to think that most people who got caught up in that bellicose hysteria experienced the attacks as a spectatorial event, as unreal, and so their reaction was also unreal – like the “payback-time” montage in an action film or the impotent revenge scenarios we play out in our heads. It wasn’t until I actually went to New York City a week after the attacks that I understood how empty and inappropriate an emotion anger was to bring to the circumstances; it was like picking fights at a wake.
He seems to have semi-retired from cartooning, but you can check out his past work here. Some of them are not safe for work.