I have managed to create a simple application (read: quick hack) to accomplish this. Started from xterm, it grabs a key (which should be the camera key) and when that key is pressed in any application then the app signals via dbus for the dashboard to appear (doesn't seem to work on desktop or in app menu). I don't have the actual device yet but it works in scratchbox. Currently the key is F10 (not sure which key the actual camera key maps to). The keypress gets eaten by my app so no other application can receive it. The app is obviously not ready to be packaged just yet, but it should prove that this is possible I'll try to make this into a real application once I receive my device. Is the lens protector mapped to a X11 keycode?