> documents. They know this concept from browsing drive C:. The idea of
> URIs that might return anything depending on the context and a dozen
> hidden parameters is not particularly user friendly and should be well
> hidden. 

One of the ways that users are convinced to accept persistent cookies is
precisely on the basis that they get content that depends on not just the
URL, but on hidden state, in this case the cookie.  From the web site's 
point of view, the most important variation is probably the adverts, which
the user may not perceive as content, but it is sold to the user in
terms of customisation of the editorial, or at least its presentation.