Brian’s Threaded Comments is a plugin that lets people either comment on a post or reply to someone’s comment (or reply to someone’s reply to a comment on a post…). I thought that would be useful after Lauren’s reply to Brad’s comment looked like a comment on the post instead of a reply (the fact that the order was messed up didn’t help either).
Besides, I like threaded comments because you can have a bit of a discussion without having a full fledged message board –not that there’s anything wrong with that.