For those who are interested, the latest issue of The New Yorker has a great article in it called "Holy Writ" by Mary Norris. Mary Norris has been a copy editor at The New Yorker for about three decades and knows pretty much everything about punctuation, especially commas. In fact, she's referred to as the magazine's "comma queen." It's a fascinating read. It's not entirely about commas, but it goes into pretty deep detail on them, using examples from the stories and articles the magazine has published (and that she worked on) during her career. Here's the link: Holy Writ, by Mary Norris. I hope the link works for you guys. I subscribe to the magazine, and I don't know if that gives me access denied to non-subscribers.