Here are 2 services that use Twitter as a blogging CMS. I think this is kind of a cool idea.
Twitblogs | The Micro-Sharing Platform
You like macro-blogging because you can use a rich combination of text, pictures and videos to express your point of view.But sometimes 140 characters is just not enough to say or show what you really want to say.If you want the best of both worlds then twitblogs is the perfect twitter companion for you. Just try it.
When its too long to tweet, just TwitWall it! TwitWall is the easy-to-use, quick-to-blast-out, instant blog companion for Twitter. With TwitWall, you can embed your favorite videos and widgets, upload your photos, mp3 music or podcasts, - you name it. Just the kind of stuff to keep your followers following (fans cheering, or clients calling). All that, while still enjoying the many social-goodness and customization features you enjoy on Twitter.