[Mithalwen]

This is one of my fuzzier ideas but is there any significance that, Denethor, as legitimate steward of Gondor has the "right" to use the palantir (although his despair overwhelms him and he does not have the strength of Aragorn)? The essay in Unfinished Tales is interesting here, noting the mental strain use of the palantiri had on the user. Boromir if I remember correctly, tries to argue at the council of Elrond that Isildur's ring should return to Gondor but of course Isildur was not the rightful master of the ring as her was of the Palantir.