WordPress has a very nice Customizable Permalink Structure. Unfortunately with the new rewrite rules (using path info) all 404's no longer get sent to the system logger.
That, my friend, is why you need the lovely Log 404 Plugin. Guess what? It sends all 404 requests to PHP's system logger, so you'll never miss a 404 again. And, it's compatible with WordPress 1.5 and 2.0!
by Introducing The Log 404 Plugin at WordPress Station (#1987)
[...] Matt’s Googly Site Apparently there’s an issue with 404 going to the system logger, so Matt Read has introduced a plugin to fix the issue, will work with 2.0 as well as 1.5. 404 WordPress // Used for showing and hiding user information in the comment form function ShowUtils() { document.getElementById("authorinfo").style.display = ""; document.getElementById("showinfo").style.display = "none"; document.getElementById("hideinfo").style.display = ""; } function HideUtils() { document.getElementById("authorinfo").style.display = "none"; document.getElementById("showinfo").style.display = ""; document.getElementById("hideinfo").style.display = "none"; } [...]