I've seen a website that shares the user database and the thread and calendar
example:
www.bmwforum.com
www.audiforum.com
www.vwforum.com
How would I have all 3 of these websites have the same login/password. And when you go to each one, the Forum list shows its own category/forums. But they are shared between all the of the websites? So if you have an account with 1 website, you are really on all 3.
Here's the example
http://www.bimmerpost.com/
he's got 4 domains, but if you go to each one individually, they show their own listing of forums, but ... its under one main forum, but they look separate
of course 2 of them have the same forum structures