I read a neat tip from Merlin Mann over at 43folders a while back that you might find helpful if you spend a lot of time in front of your computer. He was reviewing a program called Nocturne that causes your display to run in "night vision mode." The effect is kind of like looking at a negative of a photo. The tip that I found so interesting was that you can get a similar effect using a built in feature of OS X.
The magic keystroke for this built-in night vision feature is ctrl-opt-cmd(a.k.a. )-8. Go ahead and try it. Now type it again to return to normal mode. It doesn't have quite the same effect here at Geekbert since I've already chosen a reversed color scheme (see, I do care). If you are viewing a document that has black text on a white background, you'll get the right effect. It kind of reminded me of the old WordPerfect bluescreen word processing. It is a little easier on your eyes after long hours in front of the computer.
As I understand it, the benefit of using Nocturne, as opposed to using ctrl-opt--8, is that Nocturne gets rid of the crazy looking rainbow effect on colorful items in your display (looks weird just like in a photo negative). I think it does this by changing the display to gray scale before reversing (just a guess). Nocturne also automatically hides the desktop to prevent you from having to look at the freaky looking rendition of your family's photo that you use as your desktop wallpaper.
I like to use built-ins whenever possible but Nocturne is free, so check it out too and use what works best for you.
In my next entry, I'll be showing you some other tools that are available to help you with distraction free writing. Be sure to stop by again soon!