Binding screen locking to Scroll Lock in Precise (pre alpha)

$ gconftool-2 -s /apps/metacity/global_keybindings/run_command_1 -t string 'Scroll_Lock'
$ gconftool-2 -s /apps/metacity/keybinding_commands/command_1 -t string 'gnome-screensaver-command -l'