Today’s first keynote was from Jesse James Garret about User Generated Information Architecture. He mentioned Amazon to be one of the first websites to use special links to track the way a user makes throughout the whole site.
I am a long time user of openBC now and one of the most interesting features is the search. It’s not the usual search you think of on most websites. In openBC you have the possibility to see which person has looked at your profile and especially how they came to your profile.
They may have searched for your name and surname and then clicked on the search results. Or they may have clicked your profile because you are a contact of a person he’s a contact of. Actually this is not really about tagging, but the concepts they use are the ones Jesse talked about in his presentation. I think this is not that curcial to openBC (I might miss a point here) but for the user it is a very important feature.