Question on adding additional blog to main site, but from different domain
 

I run vB4.2 latest release with the blog installed in the root of the site.

I'm considering adding an additional blog (as opposed to an additional blog category) either running from a different top-level domain, or from a sub-domain of the main domain.

Is this something I can do just by copying the main blog files in vB4 and installing as an additional plug-in? Or do I need a different site license?

(Reason being that I want all registered users to be able to use both blogs from a single login).

If I need two licenses, how easy is it to bridge two installations so that all registered users can use both?