MyBlogLog is the closest to distributed social networking I've seen. There is no "claiming" of blogs, which is a bit of an issue...they'll need to add something like that soon.
They also don't have identity figured in, plus the most ridiculously long profile information pages which just underscores for me that I really never want to fill out another one of those, and I don't want to have to set privacy...I want that stuff to just work.
This might be an interesting purchase for Technorati (which just added OpenID support...).
Update: and apparently I should link to my "community".