BuddyPress.org

In respect of role management plugins I would recommend Justin Tadlocks ‘Members 0.1.1’ . Tested three out of around four or five available and found the other two mildly confusing but Justins was the most featured and usable with a useful selectable modular approach. Roles and Capabilities need to be understood though as it’s extremely easy to get things badly wrong if not sure what capabilities do what. Ability to create new Roles though does extend the flexibility of things quite a lot, even if they have the same capabilities it would allow for a form of pseudo user grouping.