BuddyPress.org

No but it’s a request that comes up every so often. It wouldn’t be too hard to create this, but I’m not sure anyone has put anything together like this yet.

A lot of this comes down to the theme and how you style the certain abilities of BuddyPress within that theme. You can also use the parent/child abilities to block different aspects of the blogs/sections of your site, which is typically what I’ve done in the past.