My blog is not a photoblog. Sometimes I post a pretty picture just because it's pretty (such as these), but for the most part pictures appear simply to illustrate whatever event I'm writing about.
On the other hand, the focus of a photoblog is not the person posting the photos, but about the photos themselves, which must stand on their own as being beautiful, interesting, thought provoking, etc.
The best example of a photoblog I've seen is Andrei Zmievski's photoblog Vu (which means “seen” in French). I've known Andrei for years, first from his engineering work with PHP, then when he worked at Yahoo!. Heck, Andrei helped me with the PHP chapter for my book's most recent edition.
I didn't know that Andrei was into photography until he started his photoblog a month ago, and in watching it I've been struck by two things: Andrei is extremely well traveled (his photos are from all over the world), and he's got an excellent eye for composition.
His style is all over the map, figuratively and literally, so it's never boring or predictable. I really like almost every photo he posts, but the true mark of excellence is that I find every photo to be interesting.
It's one of the blogs I read via Bloglines. He updates it with a new photo daily; watch it for a while and you'll be both impressed and entertained.