amarokVis is a KDE applet for libvisual using opengl.
Orginally written to work with amaroks libvisual socket however due to some limitations I just made the input default to alsa.
So any app piping sound through alsa will make the visuals dance. I was going to change the name but meh, not a big deal.
Just add it to a panel and watch the fun. If you click the visualization it'll bring up a popup box to select from available plugins.
Pretty simple and straightforward.
Beware though some plugins(actors) tend to be buggy and are likely to crash your kicker.
If that happens just restart your kicker and choose another plugin that doesn't.