One of the new features of iTunes 8 is called Genius. It basically allows you to select any song in your library, click the Genius button, and it will generate a playlist of songs from your library that it thinks go great together. I was a bit optimistic at first, but holy crap! I tried it and I suddenly feel like I have a real live DJ picking songs for me to listen to! I feel like I'm rediscovering all the music in my collection!