Command-Q is the worst keyboard shortcut ever: processes are started/stopped automatically these days, so "Quit" in many cases just means "destroy my current work session". With my keyboard layout, it's even worse, since "command" and "Q" are adjacent, so it's way too easy to do this accidentally.
I just lost a whole bunch of Firefox windows because of this.
Is there any way to disable command-Q for quitting apps?
I tried adding this menuitem to the "Keyboard Shortcuts" preference pane (as suggested here), and remapping it to command-option-Q (slightly harder to hit), and the menuitem changed to show this, but command-Q still causes the app to quit.
I'm using OS X 10.7, but I'd happily upgrade to 10.8 if it fixed this.
The app I really want this for is Firefox, but if there was a solution that disabled command-Q for every app, that would be fine, too.

