I am fairly new to Google Docs, however, I have sent drafts of preliminary swim documents to my assistant coach over at SBMS. I find it a convienient tool to use since we can see real time changes and suggestions that would normally take several emails or a phone call. We don't have the same planning period, or are even on the same campus so getting a time to call is very frustrating. Google docs have really cut processing time down.
I can envision using google docs to have students turn in projects. I could give real time feedback without the hassle of multiple emails or only speaking to the students when they are on campus.