"Since the new playlist for Amarok 2 is basically built using a QGraphicsView, we can do some really interesting stuff with it. So after playing with this for a while, and completely discarding the fist prototype I did (as the other devs managed to convince me of the error of my ways), this is what I've come up with."
http://amarok.kde.org/blog/archives/501-Playing-with-the-Playlist.html