Static GitHub powered blog engine
Blog engines were the new "cool thing to write" after the fever of writing a new DI framework was over. It was kinda like the new "hello world++" example. Almost every single engine uses a database of some sort to keep posts and comments. Almost every one is not leveraging the web as a consequence ;)
I was intrigued by the possibilities that a flexible and general-purpose hosting solution like Github could offer for a static blog engine: basically keeping plain markdown/HTML/razor/WLW/whatever files that through a publish/build time process generate static files that pass for a "blog engine". GitHub even supports custom domain names, so why not?
Such an "engine" would have a number of benefits: