Social network with wordpress?

Hi all,

I have a blog with multi authors and registered users, and I want to create sort of a “social network” with it, meaning that every author and/or registered user may have a page of himself, where he can see all of his posts/comments, and also add a friend and then see them in his page in a page list area.
Also, optional is an option to send messages between friends.

Are such things possible to be done with WordPress?
If yes, I’d be happy for some instructions and directions on how to do it.

Thanks,
M