Want to automatically save the text you type into any textarea in Firefox? Textarea Cache is a fantastic add-on for Firefox that lets you do it. This extension save the content of a WYSIWYG editor or textareas (like you see in the comments here). This is really handy if you do a long comment or post in one of these boxes and the browser caches or the webpage dies. Now you can bring your text back from the dead.
Here is a little more about the extension from the developer:
This extension will save automatically the content in textarea or WYSIWYG editor when user is typing. User can recover the saved texts in the cache window, even the tab or the window is closed unexpectedly. The user will see an icon in status bar when the text is saved in the cache. Click the icon will open the cache window. It would be useful to add the Textarea Cache button in toolbar. This button can help the user for advanced settings or to open the cache window.
This add-on for Firefox makes it really easy to save anything typed into any textarea in Firefox. If you would like to download Textarea Cache to give it a shot, you can do so at the Firefox Add-ons website.