GtkOrphan is a lightweight utility that allows users to clean up Ubuntu from orphaned packages (unused packages or packages left by uninstalled programs).
To install GtkOrphan on Ubuntu 11.04/10.10/10.04, launch the terminal and run this command:
sudo apt-get install gtkorphan
To start the tool, search "remove orphaned packages" using the dash:
GtkOrphan will now display found orphaned packages. Check on all packages you want to remove, then click OK.
For more options, click the small triangle displayed next to the Options label.