Same forum on 2 different sites (same users and posts)

[jbd]

I think it would be cool to have a mod which allows you to display the same forum on 2 different sites.

For example, users should be able to register at either forum, post at either forum, and for any posts to be displayed on both forums.

If this has already been done, I'd be grateful if someone could point me to the thread.

Cheers
James