making a backup of my linux filesystem with tar and bz2

[Nick Gawronski]

Hi, I was wanting to backup my linux system running debian unstable so I can 
keep a backup off of my system before I start installing lots of software I 
want to be able to quickly restore to a usable state with out reinstalling 
everything.  I want to make a backup of just one partition as I have linux 
on one partition and will be saving the backup to an USB flash drive that 
will be mounted as well.  What I don't want to happen is for the tar program 
to also backup all mount points and their contents but I do want it to 
backup the directories on my ext3 filesystem and the directories for the 
mount points so when I restore the backup there will be empty directories 
for my USB flash drives and not directories with all of the contents from 
the drive when the backup was made.  What would be the best command to do 
this and use bzip2 with the minus 9 compression option and preserve 
permitions and directory structure?