To make a local copy of the package selection:
dpkg –get-selections >myselections
You might transfer this file to another computer, and install it there with:
dpkg –clear-selections dpkg –set-selections
Now (If subscribed to Ubuntu One Cloud):
In Ubuntu 11.10, open the Software Center and navigate to “File>Sync Between Computers” you can see each machine hooked up and manually install the missing apps yourself. But before that you have to set up the ubuntu sync.
Note: The above method works on all Debian based systems.