Using the following method to clone all installed packages to a new installation requires the new operating system to be the same as the original (as in debian 7 => debian 7). Apt-clone will also copy the /etc/apt/sources.list. If you did install software via for example dpkg -i skype_0.8.15.deb, the switch –with-dpkg-repack will try to also include these.

First install apt-clone:
sudo apt-get install apt-clone

You can clone your packages with the following command. You will get a file called apt-clone-state-hostname.tar.gz.
sudo apt-clone clone . –with-dpkg-repack

Copy the tar.gz file to the new workstation and reinstall the packages via:
sudo apt-clone restore apt-clone-state-hostname.tar.gz