Skunk Works shares the calendar visibly by embedding it in our website. We share the ICAL address so people who choose to can view it in their calendar manager of choice. We put all the major items on that calendar. (Meetings, Provided Meals, Events, Major Deadlines, School Vacations)
For communication we use
http://groupspaces.com/. It is much nicer than Google groups, but it appears to not be a thriving company.
http://www.wildapricot.com/ is about to add ListServe functionality. Their platform has many advanced features. I hope to switch for next year. We extensively use ListServe functionality. Groupsapces handles that well. We have separate email addresses to communicate with Mentors, Design, Marketing teams, and many many more). Groupspaces also has event registration and follow-up communication features.