I would like to see a universal pivit for the bottom allowing the pole to be tilted in any direction and still be anchored down well.(a universal joint from a large trucks drive line).
Sounds like a universal pivot on the end of a pole is a great idea. A truck's u-joint, like you say, is one option. And I bet some sort of "ball and socket" configuration is possible too... maybe a large trailer hitch ball set into something, or a pintle hitch set-up.