Excellent intro to mod_rewrite. I've now converted all archive references to the much better marginalia.org/year/month/day/ (you can leave off the day to get a whole month). The great part was that once I got the rewrite rule working it only took a few minutes to have everything using the new format. Have I mentioned I love php and mysql?

One teensy note with the article - I discovered that a RewriteRule must all be on one line; the article tends to show it (on my screen) as broken over two lines.