I've seen on the xbmc wiki that there should be different visualizations available when playing back audio using XBMC. I tried this with OpenELEC but can only get the default "spectrum" effect which looks like this. If I select to add other visualizations, then the list of available ones is empty.
So maybe there aren't any other ones, or maybe the other ones haven't been ported or compiled for the pi, or maybe they have but have to be installed in a different way, maybe from a zip file or something?
Or maybe this is something that a mere mortal could develop themselves? I've seen a page on Vortex development but it's not clear that even this vortex thing works on the pi. Has anyone tried this?