THATCamp Epic Play 2013 shared Google Docs for brainstorming, notes, bibliography, and more:
drive.google.com/folderview?id=0B-hctW82Tr0dUkUwODEtdXRvQjA&usp=sharing
Participants are welcome to contribute to the existing documents or start documents of your own (these will eventually be archived by THATCamp).
You might try out Participad, too, for note-taking today — activate the plugin, set it up in Settings –> Participad, and put the Create Notepad and Notepad Info for collaborative editing goodness.