Recommended App... For Your Eyes Only: f.lux
f.lux is a little app which, according to the publisher's website "makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day".

f.lux helps computer users get peak performance out of their devices and claims to improve well-being (helps sore eyes and contributes to a good night's sleep). Just give it a try for a few days and most probably you'll see for yourself why I consider this app a must.
Available for download here in three flavours: Mac OS X, Windows and Linux
