multiple authors live cooperative editing

Hi, tonihght I’ve liveblogged the French Presidential election with a couple of co-authors (http://fistfulofeuros.net). We decided to use a single post for with updates for the liveblogging, but this choice led to a significant editing problem: If one author loads the editing form with the current version of the post at 10:24 and another one at 10:26, all the changes made author one saved at 10:28 are lost when author two saves his changes at 10:29, if he doesn’t manually reload the post at the time.

Is there a way to automatically check if a post has been saved by someone else and then warn before a post is saved? Or at least an “undo” changes plugin for recent changes to posts?

Thanks for any help!