Hello Knitty -- on white
Boy, wish I'd thought of that name -- it's taken. But here's a link to a design project titled "hello knitty" -- also image #2 below.
Creatives all over the globe use indexhibit, a mySQL-driven CMS designed for personal portfolio sites.
The CMS has a devastatingly simple design. If you want it to, the interface stays completely out of the way of the content. indexhibit.org was used as an example of "no style" style in More Eye Candy from the Underground by Curt Cloninger. It has a correspondingly simple back-end you can play with in the online demo.
Indexhibit is built by "Daniel Eatock, Jeffery Vaska And You." It doesn't compete directly with Posterous, but seems like this CMS could work for almost anything that doesn't need a social media arsenal -- see the indexhibit Idea page.
There's just something so sexy about simplicity.
Some other examples:
