The Military uses of the Palantiri.

[Andsigil]

I'd like to again point out that, while they have shortcomings as intelligence gathering devices (the ME equivalent of spy satellites) the Palantiri would be invaluable communication devices (the ME equivalent of a cell phone).

Imagine how much better coordination and response time would be between two allied kingdoms, each with a Palantir in the throne room. Mutual support would not depend on horsemen, carrying messages days or weeks old (the Red Arrow) or upon semaphore beacons, hours old which only give generic calls for aid instead of specific messages (the Beacons of Gondor).