Using testing and svg and python hacking I've put together a demonstration which works on the default lucid install: http://doctormo.org/2010/09/03/random-genetic-wallpaper/ So I may have been too hasty with my initial concerns. I think so long as the svgs limits are known, it should be possible to do something even more interesting than what I have done here.
Hey, that's very cool.
Something I wanted us to try was the idea of "convergence days", where we'd publish a data file quietly which would say "on such and such a date, try to be as close to this as possible", specifying the position and parameters of the various effects / lights / features. That way, we'd have weeks of divergence, then a "rush to convergence" over say 5 days, so on a particular day everyone's desktop looks the same again.
I thought of using constellations (playing again with "light") as inspiration, so you could have a "convergence day" like this:
