During the BlogTalk conference last month, Apple-owners in the room collectively took notes during presentations, and then published them in Joi Ito’s Wiki.
This was a pretty cool demonstration of what a collective authoring tool can do.
Via Roland Tanglao I learned that at OsCon they used a SubEthaEdit enabled wiki, which allowed direct collective authoring in a wiki-page:

This Kwiki was SubEthaEdit enabled during the convention. If you were using Mac OS X and have SubEthaEdit innstalled, you could have clicked on the icon to edit any page collaboratively in SubEthaEdit.
Like Roland, I would very much like to see this spread. Especially if SubEthaEdit will be available platform independent. That would change the landscape of convention-notetaking.