I now have several weeks' experience with Google Apps -- the suite of Google mail, documents and other tools using your own domain -- in a nonprofit organization setting. Put mildly, I'm sold on it. (Though as a nonprofit, with an "educational" account, it is free of charge.) Email admin is easier and sharing documents was an unanticipated bonus.
Detailed praise would be a drain on my now-limited blogging time but if you are interested in Google Apps feel free to contact me or leave a comment.