By default, WordPress only allows a single user account to be associated with a specific email address. If one attempts to do this, then this error is displayed:
"ERROR: This email is already registered, please choose another one."
This plugin removes that restriction: http://coffee2code.com/wp-plugins/allow-multiple-accounts/
Generate the list of installed packages. Exclude those packages that have been removed
dpkg --get-selections | grep -v deinstall > installed-packages.txt
Use this list on another system to set what to install
sudo dpkg --set-selections < installed-packages.txt
Perform the installation. Type ‘I‘ and allow dselect to install of the the packages listed in your list. When it’s finished, type ‘Q‘ and hit the ENTER key to exit dselect.
If you just want a clean list of installed packages
dpkg --get-selections | grep -v deinstall | cut -f 1 > installed-packages.txt