I know this is a thread that has long been "passed." But, I have just found this interesting ANALOGY (English class all over again, lol), and I'd hate to make it a thread of it's own, because I don't think it would spark much debate, so basically I'm trying to pop this thread back up here and see how you all think of this "analogy.
Boromir is to the Ring, as Denethor is to the Palantir.
Both the ring and the palantir are each person's, let's say "toys." Or something they greatly "have" or want to "have." It's interesting how Boromir is Denethor's sons, and they both have this "source," this "thing" to bring them to their deaths. Boromir goes for the Ring, and arguably the Palantir drives Denethor mad.