Multisite 'blog following' plugin

Hi, I was wondering if there existed a plugin that allows members of a WPMU install the ability to ‘follow/like’ other blogs within the network and have the latest articles/posts from those ‘liked’ blogs appear on a personal homepage (or the sites homepage once the user is logged in) – yes just like twitter, etc. :wink:

I think getting an ‘article feed’ from a list of user selected blogs would be a brilliant addition – any ideas?