List installed Ubuntu packages and move them to another computer

The link seems to be dead here so I've copied what I found.

"Ever forget what you had installed and find yourself at a fresh ubuntu install thinking to yourself... Damn now I gotta open up synaptic and search for everything I had... Well fortunately you dont need to do that. With this easy howto you can also restore all your packages that were installed by simply creating a package list and uninstalling every application installed after the list was made.




The following command creates a list of all the installed packages at the present time:

sudo dpkg --get-selections > /etc/package.selections

Now we created our package list and we can copy this list to a new ubuntu computer and install the same packages in the list to the new machine or, restore the packages to the time you created the package list:

sudo dpkg --set-selections < /etc/package.selections && apt-get dselect-upgrade

The above command will uninstall all packages installed after you created your restore list."