Less Wrong (http://lesswrong.com/) modified the Reddit code and made a "community blog" with long articles. The concept of blogging really has taken over this ontological niche, but there's room for a lot of variation in what you call a blog. It's flexible enough to cover everything from really long articles to tweet-at-a-time adventure serials like http://twitter.com/Othar .

I wonder what other types of blogging are still uninvented, or at least not yet popular.