Collaboration Tools: Google Docs

I have not played around much with Google Docs, but am hearing more and more people talk about using them. Wanted to point to information presented by Tom Barrett (a noted Google Docs expert) presented on the Official Google Docs Blog: New and Notes from the Google Docs Team.
Barrett has a presentation titled, Eleven Interesting Ways to Use Google Docs in the Classroom, and is asking people to email him with their tips, tricks, techniques, and uses of Google Docs.