Unity removed / no run prompt

[CrimzonEyed]

Since I never used unity I though "Hey why not remove it then".

I followed this guide to remove Unity and replace it with Gnome Shell.
http://linux-software-news-tutorials.blogspot.com/2011/10/ubuntu-1110-oneiric-remove-unity-and.html

Now I no longer have the ALT+F2 shortcut at System Settings -> Keyboard -> Shortcuts -> System, it's gone. (and not working)

Is there a way to add this shortcut again as a custom keybind?

[2F4U]

I think you have to go to Keyboard -> Shortcuts -> System and then activate the entry "Show the run command prompt" in the left pane.