just one smal thought.
as files can be mounted and "formated" with, say, iso9660, under knoppix.
And afaik ntfs allows reading and modifyind files as long as they stay the same size...
would it not be a possible way to have a persistent home.img mounted as /home on a ntfs filesystem?
Atleast as long as the *img was saved under NT, w2k, XP... or am i far wrong?

as the *img would stay the same size my tired mind tells me it might work, and as windows have programs to access content of *.iso it would b possible to share the files between the two different OS...
am i far of track now? i just got the spark of an idea, hmm, might have been a shortcircuit...
if i am, sorry i have no ntfs filesystem to try it on any more. i replacd XP with Debian...