A timeline of early blogging. They've been around for longer than one should think. I would argue that alot of the earliest ones had the form, but didn't really utilize it for much of anything. It isn't until around 1997 that things really start getting interesting.
I think I found the first one I read in winter '99 to 2000. Maybe early 2000. I remember I actually wrote it down in my diary because I thought the idea was brilliant somehow.