If we held off proposing solutions the first two days of analysis wouldn't get buried down in the first place. And to answer your question, forum posts can be edited, and the date posted is marked with an asterisk if it was. A wiki sounds sensible but it might be a little too complex for those who are unfamiliar with it, not to mention there'd be tons of editing conflicts going on. I propose Google Docs, for its real-time collaboration, or any other similar alternative. Etherpad?