BlueProximity – GNOME Bluetooth device distance detection and automatic locking tool :-): What a great idea. Of course, I keep my cell phone on my desk or in my coat pocket half the time, so I’m still screwed.
This software helps you add a little more security to your desktop. It does so by detecting one of your bluetooth devices, most likely your mobile phone, and keeping track of its distance. If you move away from your computer and the distance is above a certain level (no measurement in meters is possible) for a given time, it automatically locks your desktop (or starts any other shell command you want).