Changes to Gobuntu

Just go to System -> Administration -> Software Sources and unselect "restricted" and
"multiverse" repositories. After that you may go to eg. Synaptic, and see which packages are
marked "Local or obsolete" - you will see the packages that were from the non-free
repositories.

By default Ubuntu has about 4-6 packages installed from restricted (most just meta packages
pointing eventually to kernel-version-restricted-architecture modules package), and none from
multiverse.

Note that it lists also other packages you have installed outside repositories.