Online congregant (self-) management and (self-) organizing is going to be an important part of the new church start I'm planning. I've been waiting for Drupal 7 and CiviCRM 4 to come out before figuring out what I wanted and how I wanted to do it.
Now they out and I'll be installing the site as I have time. Using shared hosting, which would be a problem with a large group (say, denomination-grade) but should be OK with this experiment. Or so I hope.
Will share notes about the installation.