Funny, I have been mentally cataloging the trees on my land and wondering which are the tallest, since it's hard to tell when looking at them from different distances and angles. Then while I was walking around at sunset I suddenly realized there's a simple way to tell. Just as the sun is setting on a clear day, look up at the top of the trees. The last ones to be lit by the setting sun are the tallest ones (assuming the ground is relatively level of course).
It won't tell you
how tall they are, but it will point out which ones are the tallest. Heh, when you have your PBX expedition, let me know how many 350 foot redwoods you find in the pine barrens
I've spent a little time in the woods of Northern California, and those trees are awe-inspiring.