Sync.in is the latest site to use the open-sourced code from Etherpad, which was purchased by Google several months ago and closed-down.
You just paste a bunch of text in a window and, without even having to register for the service, send others the url and everybody can edit it in real time. It also has a chat option. You can go back to the url address at any time to make further, adjustments, too,
I’m adding it to The Best Online Tools For Collaboration — NOT In Real Time, where it joins several other Etherpad clones, including NetherPad, PiratePad and Primary Pad