Scenario:

You're not interacting with your system, but, you are still using it. You may be watching a film, or taking notes off a document or website. I frequently need to refer to documents.

Logic:

The default method of toggling the screen saver state would be to go to System>Preferences>Screen saver and make changes. That's too much work, and I'm too lazy for it. Here's what I came up with:

$ gconftool-2 --toggle /apps/gnome-screensaver/idle_activation_enabled

Method:

Create a simple shell script:

gconftool-2 --toggle /apps/gnome-screensaver/idle_activation_enabled
notify-send "Screen Saver status is" `gconftool-2 -g /apps/gnome-screensaver/idle_activation_enabled`

exit 0

Make it executable:

$ chmod a+x screenSaverToggle.sh

Make a new launcher:

This is what you get: