Google Docs doesn't seem to be too different from Microsoft Word. However, having it saved to my email so that I can access it from any computer with Internet capabilities is helpful. I also notice it saved the document without me having to tell it to. Plus, if I want it to, it can publish to my blog from the Docs page. Nifty.
As far as Google tools that I find especially useful: I like Google Groups. I created one for my tentative writing group. Go ahead and join if you like: http://groups.google.com/group/bigshoulderswritinggroup