37signals have been talking about their soon-to-be-released blog-based project management tool, Basecamp. I saw a preview at Blogginworks back in October. At that point it was being aimed at the clients of their graphic design firm, so some of the look had to do with the type of work one does with graphic design.
It will be interesting to see how their product develops. They've generated a lot of buzz, based on the number of comments about the basic features.