Diaspora is actually looking pretty good, I'm pleasantly surprised but am I the only one a little disappointed that they made it with Ruby? Probably. But looking through that jungle of code I wonder how far along they'd be if they had used Drupal and let that army of developers contribute with separate modules. I'd love to tinker with it but I know whatever I do will probably break it when they update their code.
What's wrong with Ruby? It's a great language.