BlueProximity is ideal tool for such scenarios, BlueProximity is a very neat, clever little application available for Ubuntu and other GNU/Linux operating systems,that allows you to lock screen as you ( carrying Mobile Phone which is paired to your Linux machine) move certain meters away from the terminal for a duration of time, and unlocks it automatically as you( with the Mobile Phone) come back within range of the computer. As the name suggests, Blueproximity talks to Phone through Bluetooth.
BlueProximity is available in the Ubuntu repositories and could be installed very easily by issuing the following command in the Terminal Window :
sudo apt-get install blueproximityThis should install blueproximity , you can launch blueproximity from (Applications -> Accessories -> BlueProximity ).
Caution : You would need to have bluez or the Linux bluetooth stack to be installed on your computer before (if it is not already), you can do so by issuing the command sudo apt-get install bluez
Once you have installed blueproximity, first you need to pair your bluetooth device which is your Phone with BlueProximity, so that it can communicate with device and find out its distance from the computer.
Once you have paired your phone with BlueProximity, you need to configure the distance phone should go out of reach of radio on Laptop before blueproximity locks, the duration as well as the range within which phone has to come back for blueproximity to unlock the computer screen. This can be done through options presented under ProximityDetails tab.
Blueproximity locks screen by calling gnome-screensaver with different parameters when phone goes out of range, however, if you want, you can call different application as well, I can think of some really creative choice(s) of application there!
Application to call when phone goes out or within range, notice option to log all the events.Overall, this is a pretty neat and simple application which could be immensely useful for some people, though the only problem I have with use BlueProximity is, keeping Bluetooth on, on my old laptop or a old Nokia phone is going to drain battery and this is a serious drawback, though still it is very useful.
Now, you are ready to test this, take your mobile phone and move some distance away from the computer, your computer should lock screen and as you approach laptop again, the screen should be unlocked.
Useful links -
Blueproximity sourceforge page - http://sourceforge.net/projects/blueproximity/
Ubuntu Forums Thread - http://ubuntuforums.org/showthread.php?t=702372
( This could be useful if you run into trouble with blueproximity, this could be ideal source to ask question as well in case of problem in using blueproximity)
Article Written by : Ambuj Varshney (firstname.lastname@example.org)
For Linux on Desktop Blog , http://linuxondesktop.blogspot.com
(C) 2011 , Ambuj Varshney