Brightside is a program which can trigger commands when “hot” sections of the screen (in this case, the corners) are hovered over. This tutorial will use the top left corner to lock the desktop, but equally, and of the corners could be used.
To get this working, two packages need to be installed and configured and two script files need to be adjusted.
First, install brightside and gnome-screensaver
apt-get install brightside gnome-screensaver
Next, configure both using the commands
Add the following lines to /usr/bin/startsimple.sh
/usr/bin/gnome-screensaver & /usr/bin/brightside & /usr/bin/gnome-screensaver-command --lock
Also edit /etc/acpi/btnlid.sh, and add this line after the if statement
su user -c 'DISPLAY=:0 /usr/bin/gnome-screensaver-command --lock'
Some of these paths may not be perfect but should start you on the route to a slightly more secure EEE PC