Well, buying a laptop kind of defies the whole idea of having a portable OS with you. With a laptop you have both hardware AND software. In my solution (which by the way: more and more distro's are now made to work from a USB stick!) you have a portable OS that you can use with any (host) hardware/PC.

But reasearching some more into this subject already made me come up with something I think would be the scenario needed to achieve this:

1) 2 partitions on my HDD: one that is either fat16 or 32 to be able to boot from (probably emulating either a LS120 floppy or just USB-boot)
2) Have the DVD image on its own partition
3) have some sort of bootsector that loads the DVD image, boot Knoppix and start
4) use the fat partition to be able to 'share' files between Knoppix and other OS's, write all settings etc... (home/dir)

I was just hoping that anyone could somehow guide me on how to achieve all that....

PS: I do run SUSE 9.3 Professional on a desktopsystem as a secondary OS, and I have used both Red Hat (untill it became commercial) and Mandrake (untill it became Mandriva) so I do have limited Linux experience....