Wonderful paper by danah boyd http://www.firstmonday.org/issues/issue11_12/boyd/index.html that I was reminded about from Scoble's blog http://scobleizer.com/2007/06/20/defining-friending/ the twitter fiend.
Personally - I am going to create an official friend linkedin policy after recieving numerous requests to recommend people to friends of mine. Some of those I was perfectly comfortable making - some of those I was not. How to handle the fact that people I barely know might be representing themselves as near and dear friends?
I so want "levels" of friendship in our open source social network!