I think Google Docs are an amazing tool. We have already used Google Docs in my school to collaborate within our Pod (A Pod is a teaching team of ELA, Science, Math, and Social Studies teachers who work together with the same general population of students). We manage our discipline issues within the pod, and we were finding that we were having trouble communicating the number of students who were getting written up in each of our classes within a day. We noticed that Little Jose was getting into trouble in each of our classes and we needed a way to collaborate and share in a minute-to-minute way. Enter Google Docs. We found we were able to create a graphic of students for whom we wrote citations and include the consequence instantly. That way, if necessary, if Little Jose got in trouble in every class, we would know with a click the specific consequence to dole out.
Two, Google Docs also is a way to cut down on department meetings. Have the "meeting" on Google Docs instead! That way, productivity is increased and meaningless meeting times, in which teachers generally get off track from the agenda (if there is one) is diminished.
Finally, a cool classroom application of Google Docs would be group activities in which students need to communicate with one another OUTSIDE the classroom walls. Say they have been assigned an activity with multiple parts. Google Docs enables students to make assignments with each other in the classroom and follow up with each other on Google Docs after school hours. If Johnny has a questions for Penelope, they can log in and dialogue about it through their work in Google Docs.
I think between Google Docs and Edmodo, students and teachers can improve their communication and engagement one hundred-fold!