Two Facebook quickies :
1) Just caught myself surfing the videos on friends' FunWalls etc. Ouch! But from this I conclude that social routing of media is viable. Been watching stupid stuff that I probably wouldn't have watched on YouTube, and certainly not on TV.
2) I'm very intrigued by the FriendCircles application. It's the first third-party app. I've seen which effectively lets you define new categories and sub-categories of relationships with people. This is a functionality that Facebook seem to be neglecting but something like FriendCircle could provide, and in doing so, itself become a platform on a platform (and so proceed ad infinitum.)