Disable <super>-s (i.e. <mod4>-s) keyboard shortcut in 12.04
If you're in Unity 3D, you can go to
gff --no-gui -setparam="CCSM/Expo/Keyboard\ Shortcut/*" setflag("disabled")
OR in human terms/you don't know what gff is: Open up CompizConfig-Settings-Manager, then go to "Expo", then inside the first tab "Keybinds" there should be a keybind called "Activate", click on the pencil next to it, and write "disabled"