After all the hubris last time I posted something about copyright I'm a little gun shy but here goes:
Needed some footage of one of our landmarks for a clients DVD. I had some copyright material produced by our state government tourism board.
Not wanting to expose myself and my client to any expensive litigation I rang them, The answer, "Not a problem, send us an email and we'll send you written authroisation".
Now this isn't a commerical product I'm making, things may be a bit different in that case. But it does underline the point that firstly there must be heaps of this kinds of footage around if you ask nicely and secondly a simple phone call can let you sleep a lot better.
To shoot the same footage myslef I'd have been looking at at least $5,000 by the time I paid for the chopper, the gyro mounts and a camera and the insurance.