Google Docs Update, K-12

http://googleblog.blogspot.com/2011/03/great-documents-come-from-great.html
Teachers and students have been using the comments and feedback features for collaboration. Google believes that the discussion about a document is as important as the document itself, but until now, there hasn’t been a great medium for this discussion to happen. Recently, Google expanded the comments into “discussions,” making them editable, making them appear in threaded conversations, and letting collaborators use the @ symbol to refer to each other by name.

Go to the above URL for a sort video of these enhancements.