Well, may not be OT after all. Here goes...
I moved to a detached house last year, and the back garden is backing to a long strip of woods that is protected by Scottish Heritage, and hence cannot be touched. The trees are all around 30m high or so.
Unfortunately when the Sky installers came to have a look a few months ago they very quickly established that the dish should point straight at one of the trees, and there was no chance of getting any decent signal. We gave up on the venture at the time, but after a few months of Freeview (appalling!, but that's another story), we decided to try and see if there is anything that can be done about it.
Putting the dish at the top of our chimney will still only reach around 80% of the height of the (very dense) trees. Also, despite our garden being is very big, all of it is "covered" by the trees, so no chance of positioning the dish anywhere.
Oh, and NTL serve houses less than 100m from ours, but have no intention of covering our street...
Does anyone have any experience with dealing with a situation like this one? Should we simply admit defeat and move on?