http://www.oceansideurc.org/ - Home (Daniel uses Squarespace.com. It's a nice all-in-one solution but has a few limitations. The solution supports using your own domain names too.)
Christ Church PCA » Home (Fred built this from Wordpress. Wordpress has added some plugins and features that have made it more suitable for this kind of work though it is still a bit clumsy at other things. For what he's doing with it though it is really quite nice.)
Two other CMS's worth looking at are
Joomla! and
drupal.org | Community plumbing
Of the two I prefer the former in terms of where it is going technically.