I've always found a good old ullulation will normally remove those that wish to block my view at gigs (I can be a literal pain in the ear.....). Until they started getting civilised in cinemas (and put the screens higher up) I just used to sit on the seat without folding it down.

I must say that I've only really had a couple of instances where the tall person has been deliberately rude or unhelpful. On the whole they've been willing to swaps seats with their shorter companions, swap seats with me or even just slide down in the seat till I can see. Tall people are generally very helpfull toward me in supermarkets where they stock everything I want on the top shelf and I have returned the favour by finding stuff they can see on the bottom shelves.

TTFN Lady P.