[orca-list] backing up a desktop and a laptop

[Michael Weaver <weavermicha googlemail com>]

I am thinking of using Deja-dup for backing up my Linux systems and I
know that it works fairly well with Orca.
However I have a question which is I have a desktop and a laptop which
both run Ubuntu so if I were to backup both systems with Deja-dup or
some other backup tool could I use the same media to backup both as long
as I was using the same distro of Linux which in my case is Ubuntu or
would I need backups for separate systems regardless of running the same
operating system?
At the moment I have Lucid Lynx on my Desktop and am testing Maverick on
my laptop so in that case would I need two USB sticks or CDs or DVDs etc
for both systems?