I installed the program and it automatically adjusts the brightness of my screen to the time of day in my location. For me the problem is solved. I occasionally adjust the brightness now manually.
I would be interested in hearing comments from others on this subject.
@tiagoalisson - The easiest thing to do in your case would probably be to just invert the colors on your computer. On Windows, I believe the hotkey is Shift+Alt+Print Screen. A quick Google search shows that the hotkey for Ubuntu 10.04 is Super+N/Super+M.
By the way, what you linked to above appears to be a user created plugin/style, not something that Facebook or Google put out themselves…
In case anyone wants to know… f.lux works on Ubuntu 11.04 with no problems for me. (I’m going to switch back to Windows next week after a year of using Linux though I’ll miss it)