According to Robert Ambrogi of Legal Blog Watch, it may have been me (Jul. 16; more). I actually don’t remember whether there were any other law-related blogs when I started out eight years ago. Pioneers like Eugene Volokh were at that point doing things on the internet, but not yet blogging. It’s also possible that there might have been something going that is no longer published, so that Overlawyered might qualify as the oldest surviving legal blog.
Our very first post is here. For several days after that I believe the only reader was me, since I waited until a few posts were up before I began notifying friends about the site.
Also, David Giacalone contributes a haiku for the occasion (scroll).