Etherpad

(thanks to Amit Agarwal at Digital Inspiration)

Etherpad  is a collaborative online writing tool where multiple authors can edit a  document simultaneously and view changes in near real-time. A  particularly cool feature is the Time Slider, which will play back your writing process for you, replete with corrections, edits, and revisions.  I'm not sure what you'd use it for,  but it sure  provides a striking demonstration of how much refining and editing goes into even the simplest bit of word processing...and makes you wonder how we managed to write anything at all when such editing options weren't available!Here's a link that shows you the genesis of an earlier version of this post - just click the play button.