Borderless, transparent background mode
It would be cool if the visualization window could be set play as an overlay (alpha blending with rest of the desktop). Rolling over visualization region would bring up handle icon to move and near the edges, resize. This would allow Plane9 to act as a aesthetically pleasing wallpaper overlay.
CJ W commented
I'll 2nd that. Also would allow visualizations over videos (like a VLC playlist of random videos running as the background)