I'm no help for you there, sir. If you're looking for a Live CD like Knoppix you're basically SOL unless you want to go with Gentoo. And it's not quite clean yet, I think:
http://ask.slashdot.org/article.pl?sid=04/11/03/0224231
If you're looking for a full install, you'll have to start downloading....I think most of the main distributions come in a PPC (Mac) flavor.