Has anyone ever heard of a blog being used as a Choose Your Own Adventure-style gamebook? Something along the lines of TSR's Endless Quest series. A 'gameblog'.
It could be done of course, with the choices leading to different posts instead of pages. It might be best built up as a closed blog and made public when finished, in that it wouldn't be much fun as a reader to have to wait for the right post for days or even weeks. That said, because editing past posts is possible, a short adventure could be put up and developed with parallel routes or extra locations over time.
Adding in the combat elements of Fighting Fantasy would be simple too, and could even be done with gadgets. The linked narratives of the Lone Wolf series could be recreated by linking blogs. In fact, a project like this could span many blogs, with characters able to leave one narrative and join another when the opening comes.
Interesting idea, right?
Update: It's well underway now and the starting point is here.