I have seen several submissions here about improving Ubuntu's look and feel/better wallpapers/remove the old and lame screensavers, etc. etc., and I agree that all of the above ought to be done. Eyecandy improves the appeal of the OS -> Increased Appeal = Increased Adoption.

A while ago, while looking through my long list of boring screensavers, I thought "some of the iTunes Visualizers would make great screensavers..." Perhaps the screensaver could even play tracks from your fave playlist (after all, it would need some audio input to make it dance). Also, I just had a look at a few 3D Desktop demos using Compiz (http://www.youtube.com/watch?v=ZxfSwzhSn1c&feature=related ). So how about 3D visualizer-screensavers. Start with something like 3D versions of Euphoria or Skyrocket (imagine flying through a Google-Earth cityscape with fireworks exploding in sync with your tunes) or...