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but... what do you want to achieve with that?
uh .. in this way you can show many sites of same content. Did you ever thought about that searchengines will not like those "virtual dublicate content" pages?
I wouldn't advise anyone to link on his pages this way. Or, especially, not on 2 or more different ways. Google will note this as a supplemental result.
using .htacces to rewrite urls is not the only thing if pathes and existing links to pages without rewrites are still there isn't it?
michael