In 12.04 (Unity), I would like to assign a shortcut to the "always on top option" for a window. Probably something like Ctrl+Shift+Home to turn on and Ctrl+Shift+End to turn off, or whatever. Is there an option to do this somewhere in the Compiz Settings Manager?

This (old) post claimed that

For compiz, Enable Extra WM Actions. Check the properties, and insert ALT+A to Key field for Toggle Always-On-Top action.

But I couldn't find that.