This is a screenshot from the project M visualizations. I took random screenshots and selected the ones which can work as a wallpaper. Project M visualizations, once installed as one package, will add about 500 visualizations to Amarok.
Edit: Everytime I scroll by this wallpaper I have to laugh. And the more it's voted down the more I'm laughing, because I just imagine these people who go like: "What? Ewwww! Don't like that one."