Once is happenstance. Twice is coincidence. Three times is enemy action. Four times is Official GNOME Policy.
- Press the 'Menu' key on the keyboard
- Press 'Esc'
- Focus is now beneath the screen locker
- Press Alt+F2
- Start 'gnome-terminal'
This was sent to bugtraq a couple days ago, but it was actually reported two months before the similar GNOME bug that I ridiculed last year.
And here's another variant of it from August, which is possibly even easier: "Holding menu key causes window flood and desktop freeze." This probably means "hold down the Menu or Super key and wait for gnome-screensaver to run out of memory and crash, unlocking the screen."