Shortcutd is now available in extras-devel. IF YOU DON'T KNOW WHAT YOU ARE DOING, DON'T GO THERE, IT MAY HURT YOU.

This is a daemon for handling proximity sensor and camera key to access dashboard (task switcher) and phone application. Key features at the moment:

-press camera key when the lens cover is closed to access dashboard
-touch proximity sensor briefly (two vibrations) to access dashboard
-touch proximity sensor longer (three vibrations) to access phone application
-touch sensor much longer (~3s) to disable sensor (long vibration). Do it again (long vibration) to bring sensor again
-proximity sensor can be disabled permanently by editing config file:

-application requires proximityd
-app enters power saving mode when keyboard is locked

This is just first and basic preview and there are known issues at the moment:

-after unblocking the phone (slider, power button, keyboard) it can take up to 5 seconds for the application to activate. This is related to the power saving mode.
-Everything is basic and rough, to remove just uninstall the application.

About energy: it enters the power saving mode when you lock your keyboard/phone, so no impact there.