I realize that this post is nearly a week overdue, and it does not behoove me to neglect mentioning it. Last Sunday was the book signing for William Gibson's latest novel, Zero History. Rather than one of the bookstores a bit closer to home, it was held at Politics and Prose, a small-ish bookstore square in the heart of northwestern Washington, DC. It's reasonably easy to get to by Metro, though you should keep in mind that you'll have a bit of a hike ahead of you. From the Metro station it was about five blocks uphill, not so …