http://www.knoppix.net/forum/viewtopic.php?t=3626

This is the original post, about Knoppix running on VPC6 under OSX; it's slow and nasty, but I imagine it would be easy to make a Debian port to Mac OSX. I don't remember the site, but there was a very popular howto on running Debian on an iBook. Maybe you could google it and come up with some better results? Keep me posted on your progress. ^_^