Firefox with Stylish: User style WriteRoom for Google Docs turns your browser into a distraction-free editing tool.
Once installed, the user style hides everything on the screen, sets a darker background colour, increases the size of the text, and sets a maximum width so you can more easily focus on what you are reading. Using the F11 key to put Firefox into full-screen mode completes the effect, leaving you with a completely distraction-free environment. While you can technically install the user style with Greasemonkey, only the Stylish extension allows you to easily toggle the style on or off—which is required in order to use the save button when you are done writing.
WriteRoom for Google Docs is a free download, requires Firefox with the Stylish extension. For more distraction-free editing environments, check out the portable Write Monkey application, or learn how to turn Microsoft Word into a distraction-free editor.
WriteRoom for Google Docs [userstyles.org]