One feature that may be interesting is to allow a user to register into dotLRN with a "domain'. This domain can be a code number or word associated with the user. Multiple users can use the same domain. Then a community admin can add members from that domain provided they know the code or domain name. This would allow users to join a dotLRN instance and be added to communities without allowing all community admins to see potential members. That is, if I am a club admin and I want to add a member I can see all the members in the instance.