Automatically Save Text Fields As-You-Type with AutoSaveTextToCookie [Featured Firefox Extension]
Firefox only (Windows/Linux): Firefox extension AutoSaveTextToCookie saves everything you type in text boxes to a local browser cookie with every keystroke so that in the event of a browser crash or inadvertent tab close, you won't lose your precious words. In my tests, it worked just as advertised, making this one of those great Firefox extension that does one simple thing and does it well. AutoSaveTextToCookie is free, works in Windows and Linux only.