Don’t do this.
I can understand not appreciating a negative review of one’s work, but Joseph Larkin takes, I think, an ill-considered approach in his response.
EDIT 5/23/09: Huh. On his own blog, this cartoonist links to several comic bloggers who’ve commented on his behavior, and calls us all fat, sexless losers. Boy, he sure showed us, what with his comedic genius an’ all.