rakaz, maker of some very nice Firefox wallpapers, also has a set of forum and IM avatars. Very nice if you want to show your support for Firefox and perhaps get a few IE-using friends to ask you about your avatar. Anyway, that wasn't the reason I was looking for avatars. The reason was me coming across Tom Werner's Gravatars (or Globally Recognized Avatars).
Looks like a cool thing to implement on this weblog. There's a WordPress plugin, but plugins don't work on the nightly I'm using so I'll probably wait until WordPress 1.3, or if I ever get my butt off to try to get a CVS version to work.
(And yes, this is a concise, rushed entry because I've got my Half-Life 2. It's Half-Life 2 weekend!)