Incidentally, I am not a big fan of comments. I think they are often an artifact of using weak languages. I think that programming languages should be a good enough way to express programs that you don't have to scrawl additional clarifications on your source code. It would be a bad sign, don't you think, if a novelist had to print notes in the margins saying "she left without saying anything because she was angry about the trampled petunias?" It is the job of the novel to make that clear. I think this is what SICP means when they say "programs must be written for people to read, and only incidentally for machines to execute." I use comments mostly to apologize/warn about hacks, kludges, limitations, etc.
This is in the context of PG defending his claim Succinctness is Power for a programming language. Love him or hate him, you cannot ignore him. I think he is a true thoughtleader in the programming languages community ..