As stories can be told in first person, or third person, in the form of a diary or a tale, as book or comic or movie; I was thinking that blogging could be a literarly style as well.
I can think of two sub-genres. Historic and fantastic blogging.
For historic imagine a blog written in the context of -70 (minus 70) years. So that on October 19th 2009 you’d get a post for October 19th 1939. Who would be the blogger? It could be an important person, what would Churchil blog? Or it could be an unnamed person, an anti-nazi frenchman for example. They could also have a Twitter account! It would be an interesting way to learn history.
The other genre would be total fantasy. A blogger in the future, imagine if for some strange reason, blog posts of a guy surviving the singularity travel back in time? What if blog posts from a galaxy far away? I would certainly follow those blogs! But of course, it’s hard work that requires a very good writer.
Another thing that could be applied to any fictional blogging is having a network of blogs. Imagine reading the blogs of a frenchman in the resistance, a nazi soldier, a Russian red-army member. All blogging about the same, from different perspective! What about reading the Twitter feeds of Frodo, Sam, Gandalf, Aragorn, Saruman?
I think it would be very entertaining.