cloning a desktop to a notebook

I'm building two new work systems; installing Kubuntu on
A) a desktop and
B) a notebook.

Both are i386 so there are no architecture differences.  There are of
course differences in RAM, and disk space.  However, I'm installing
binary packages.

The desktop is pretty much done.  I started building the notebook
(meaning point and click through the package manager).  Rather than
try to chase down all the software I'd like to install, I'd rather
just clone the desktop system.  I figured the most straightforward way
to install all the packages that are on system A onto system B is to
just list the installed packages and feed that into a apt-get install

system A
dpkg-query -l|cut -d ' ' -f 3 |xargs echo -n > package-list.txt

system B
sudo apt-get install -f package-list.txt

Any better approaches?  Any reasons this will blown up in my face?

Thanks,

-- Greg