<<Some years back in a debate with Rich - yes, the one and the same - he brought up an excellent point about circumcision. I believe he said something like even if you doubt doing it, it's for the best for the son to look like the father, that it would make those issues easier (fewer questions, etc.)>>
Never entered into my consideration, though I've heard it before. In the first place, I don't stand around comparing pricks with my son, and in the second place, I ENCOURAGED all my kids to ask questions about anything and everything. We never thought that issues had to be easy. We don't live in an easy world.
Pure and simple, it's tradition, encouraged by a small party (well, it's supposed to be a small party) and the fear that your son will grow up to despise you if you broke the chain only after his birth, like he was too delicate to suffer what is only a few seconds of pain. Plus the fact that you don't really know if there's a God or not, but there's a sense that if there is one, you don't want to piss him off on what could be a potentially major issue.
The biggest argument against, IMHO, is that it might be desensitizing the head of the penis and depriving the kid of an extra measure of sexual pleasure that nobody ever misses because nobody (except the uncircumcized) ever knows.