Lets say I had a machine dual booting XP and Linux (assume ubuntu but the
question is generic) and using grub.  Now lets say I want to do a clean
install of Linux (not necessarily the same distro/version).  I assume the
cleanest way would be to restore the XP MBR, remove the Linux partitions and
then re-install Linux.  Very ugly so I am hoping there are better ways.  For
example, if the home FS were a separate partition, it might save a lot of
restorative time but I would have no idea of the mechanics.  Can anyone
point me to a resource that would help explain the issues and methods for
REinstalling Linux.

BTW, my need for doing this is gone so please do not spend a lot of effort
answering this.  If anyone wants to know WHY the question came up I would be
happy to explain though.

-- 
Be who you are and say what you feel, because those who mind don't matter
and those who matter don't mind.  - Dr. Seuss