Fullscreen HTML Editor is a plugin by jbleuzen that will allow you to completely focus on the content you are writing in your HTML editor. Install the plugin, use it and write without distractions.
The plugin adds a new button to the Editor.
We have been trying this, so far without any problem, this is a great add-on for anyone preparing large articles in the WordPress editor.
Requires WordPress Version: 3.0 or higher Compatible up to: 3.0.4
Download and info: http://wordpress.org/extend/plugins/fullscreen-html-editor/