Rescue Shortcuts for "Frozen" OS X? Though it doesn't happen often, I sometimes find myself in the situation where OSX will not respond to any commands.

The last time this happened I was closing a fullscreen VM - the app went away but then I was on an empty screen and wasn't able to switch away (the mouse still worked but not the brightness/volume keys).

Is there any way to escape from such a situation other than holding the power key?

(I only found a few shortcuts that are supposed to force quit but none of them worked. Some mentioned an "EJECT" key which I do not have on my MacBook Pro keyboard.)
From the article at http://support.apple.com/kb/ht3411

Press Command-Option-Esc to force quit, it brings up a dialog so you can choose which app to quit.

Command-Option-Shift-Esc for three seconds will force quit the front-most application.

Here is another helpful article: http://osxdaily.com/2012/03/02/force-quit-mac-apps/