I've talked about MoodLogic before. In many ways, it is the precursor to things like Pandora. It was created by a very smart guy who used user data to collect information about songs that is much deeper than what is available from CDDB, AMG, etc (ironically, his company was acquired by one of the others, but that is a different story). I was building a few playlists because it is time to hit the gym after gaining a few pounds in the pre-launch run-up. I remembered how good ML was and decided to see if anything had been changed. It turns out, they have released a new version (v2). I don't know when they did it, but one of the new features is that is it free for your first 10,000 songs. That is very cool. I'm busy building new playlists as we speak. Just curious, do you guys have any tools for building contextual playlists that I don't know about?