[CentOS] Help with backups

I've got a Redhat 5 server running Samba, and two dualboot CentOS 5 
workstations.

Until we get a better backup strategy, I'm backing up the workstations to the 
server via mounting a shared samba drive to /mnt.

Trying tar cvf /mnt/samba_share/backup.tar /* eventually yields backing up 
/mnt, which produces an unwanted loop, including /mnt/samba_share

I looked at tar with --exclude /mnt but didn't seem to get the results I 
wanted.

I tried dump, which looked like it was working, but I have no idea what files 
it was backing up, and couldn't find an option in the man page to have it show 
me the files.  I would have let it go, but since I couldn't be sure about /mnt 
recusion, I opted out of it.

I ended up, for now, tarring each top-level directory to its own tar file, 
except, of course, for /mnt.

What do people suggest?

Thanks.

Scott