Not really applicable at the moment, but LordHavoc and I were talking about the possibility of using particle tracing for map lighting. basically it sends millions of "light particles" out, and they bounce off of surfaces and whatnot like real light particles do. The longer you let it run, the less splotchy it becomes, because the distribution of particles is better. I googled around for some images of things rendered using this method and came across this site:
http://www.raumpartikel.de/mainFrameset.htm?subsites/projects/free.htm~contentThe kind of cool thing about it is that you could run it for any period of time -- the longer it runs, the better it'd look. It would also be easy to do distributed compiling, as each machine could run a bunch of particles, then at the end, you'd just merge the results together.
