Despite the fact that I don’t use Gmail as my primary point of contact, I do use most of Google’s other tools quite a lot. In particular, I’m a big fan of Google Calendar, Docs and Groups, and I use all of them for various work and non work projects. It’s now possible to share documents and calendars with all members of a particular group, which makes administering sharing a whole lot easier.
So yes, if you’re still using yahoo groups for your project, or you still rely on a word document emailed around with “tracked changes”, then there is a viable (and easier) alternative.