Render time for bagginsbill's Environmental Sphere with one infinite light and with indirect diffuse lighting turned on -- is much faster if you use Semidieu's Advanced Render Settings Python Scripts. It took hours without the script and only a few minutes using the script. I believe Semidieu's script will check for the number of processors your computer has and use them. (I have an Intel Core Duo Extreme in an iMac). It may also make better use of your ram, but I'm not the one who can really tell a thing like that. Anyway, this definitely speeds up the rendering.