When TBL speaks, I listen:

"Right now, so many people are complaining that they have told one Web
site who their friends are, and another one who their friends are…In
five years time, I hope people will be programming not at the document
level, but at the application level.  You will have something
which is an application which is consistent for looking at different
aspects of people. It (will use) your role as their friend for putting
together a very powerful, all-encompassing view of them (online)."