Like most things in drupal there are several ways to do this.  I imagine you could do it using the multiple sites setup but I haven't tried that yet.  I might do it by developing 2 templates that call different navigations and logos and work it that way.  you could again do this in several different ways but the best way would probably be to set the different nav blocks to the same region but set them to appear on b and b/* or a and a/* depending on the site you want them to appear on.  It feels to me like you will run into other issues because of the many things that drupal assumes for you - all solvable but perhaps frustrating.  But I don't know what those issues would be. 


Fred Jones wrote: 
I have a.com and b.com. Both will point to the same place. On home page 
we have two links: A and B.

A goes to a.com/a/ and B to a.com/b/. Thus all pages will be somewhere 
on a.com.

So each 'site' is really just a subsite of one site. The layout is 
virtually the same for each--only difference is the logo and the link to 
the other site (A links to B in the footer and vice versa). The menus 
and content for each site are entirely unique.

How should I set this up?

Either directions or a link for further reading would be appreciated.

Thanks,
Fred

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sander-martijn
interface developer | architect
sander@sander-martijn.com
www.sander-martijn.com