Webjam does what I had hoped Google Sites would do. It offers a collaborative system using modules and themes which enables a group to build and maintain a website.
And it works.
I've created the East Midlands Speakers Club website using Webjam, with a blog and bulletin on the front page. I've been able to add a Google map showing the location of our meetings and also a Google calendar.
Because of the faffy way Google goes about things, I couldn't just drop and drag a calendar. I had to copy the code and paste it into the html, but Webjam still made that process easy.
Parts of the website can be limited to group members, which might have its uses.
Two members of our club have signed up as co-editors. I just need some information to write up now.