I had severe problems with flux under Ubuntu so I switched to redshift:

http://jonls.dk/redshift/

Everybody should try a program like this, during the night/evening it is so much better then the normal color configuration!

I use the Antec lights described in the post; you can see a picture of them in the dark here: http://jseliger.com/2011/10/07/steve-jobs-passes-and-the-int... . They're a definite improvement but don't provide a huge amount of light. But it's enough to make a difference. Plus, they're really cheap, at $12 from Amazon: http://www.amazon.com/Antec-Halo-LED-Bias-Lighting/dp/B0053B...

Knew this would come up. It actually changes the colour temperature, so that it more closely matches that of artificial light once the sun has gone down. It does take some getting used to, but theres no way i'd ever go back now. Turning my screen back to its 'normal' colour temperature of 6500K at night looks positively radioactive.

Set it to slow transition, then you really don't notice it. (FWIW i use 3700K at night). This along with the rear-based lighting from the article is so much better to look at.

Pro-forma agree. In the past few years, the few nights I've had trouble sleeping all turned out to be nights I accidentally disabled Flux and didn't notice.

Agreed. F.lux is a fantastic piece of software.

I found it tended to try and dim my screen while I'm in the middle of gaming and caused my whole system to slow to a crawl and would sometimes crash my computer completely.