BRL,
I think what sky farmer is suggesting is that the same thread would exist in more than one forum. So any edits or replys would automatically appear on the thread in both forums.
This is not really multiple postings in the sence that they are seperate postings. ie. nobody can go reasearching an answer to suddenly find someone else answered it in another forum, as any reply would appear in both forums simultaniously.
It seems like a good idea to me