I was more thinking of a single forum install.  But depending on the user they could only access certain forums.   So any user who registered could only see the basic forums but then there are other forums an administrator could give them access to depending on who they were.

Looking for some forum software to implement and I think PunBB looks very nice.  Wondering if the following two features are available?

1. Allow users to login with their email address? I set up an account here but it uses the username terminology and requires user name to be used to login.  Personally I would prefer to just have people sign in with email address.

2. Would like to have a single installation and user directory serve a few different web sites.  Thus if someone logged in from Web Site #1 they would see a certain list of forums.  If someone logged in from Web Site #2 they could see a different list of available forums.   Is something like this configurable without having to create a new mySQL database and installation of PunBB?

Thanks!