I've been posting on this before, but couldn't really express what I needed. Now I think I got it.
I got 3 domains, belonging to the same organization in 3 different countries: Denmark, Norway and Sweden. Each country should have its own website, in it's own language. However, since our languages are mutually intelligible, I want news (posts) posted in any of the 3 languages on all 3 domains, while headers and pages should be unique to each domain (each domain have will have its own language). That's tricky, isn't it?
I suspect it's not possible to have multiple blogs with the same DB for posts but different for pages, but is there a way to get the same effect?