F.lux - Colour Temperature Adjustment

f.lux is a app that changes/adapts colour temperature of your display during the day.
By adapting the colour temperature for the time of the day it will make your screen more viewable and it is good for your eyes.

f.lux makes your computer screen look like the room you're in, all the time. When the sun sets, it makes your computer look like your indoor lights. In the morning, it makes things look like sunlight again.
Tell f.lux what kind of lighting you have, and where you live. Then forget about it. F.lux will do the rest, automatically.

 To install f.lux you first need to add PPA

sudo add-apt-repository ppa:kilian/f.lux
sudo apt-get update
sudo apt-get install fluxgui

f.lux is only not available for Ubuntu 11.10 but you can install one for Ubuntu 11.04 (https://launchpad.net/~kilian/+archive/f.lux/+files/fluxgui_1.1.8_all.deb)

When you first time start f.lux it will ask you for location (latitude and longitude)

You can easy find your latitude and longitude by clicking link in menu (http://stereopsis.com/flux/map.html) (here is another site if first one is not working http://itouchmap.com/latlong.html)

Now just leave f.lux running and it will do the rest.

At first you may think that this in not good for you but when you turn f.lux off and screen will become bright and you will notice that f.lux is good for your eyes :)