I personally believe that the iPod is a frankly corrosive device because it encourages you to surround yourself with your favorites. The whole idea of a playlist is to surround yourself with your favorite things, and the interesting thing is that when you do that, they cease to be your favorites.
I'm predicting that we'll finally have a computer will search my e-mail automatically and delete every message that begins with 'thought you'd be interested,' and then give an electrical shock to the sender to remind him or her to stop send that kind of message.