this is little hack will add a new feature for toshiba satellite m40 and compatible notebooks. The new feature is called lastfn and gives
$ cat /proc/omnibook/lastfn
last fn pressed: 64
at every cat the key event is sent to kbd so that it can be bind through your normal application (in my case, gnome-keybinding-properties).
This little script completes the hack
$ cat watch_proc-omnibook-lastfn
watch --interval 0.1 'cat /proc/omnibook/lastfn'
watch will take care that cat is being processed quite often so that no keys are missed.