Some of you know I'm hoping to achieve self-sustainability here in a few years; this gives me a big leg up on the protein issue. I'd been thinking toward depending on our black walnut trees-- I counted yesterday, and there are 13 surrounding the garden! -- and the single pecan out back. The walnuts present a problem, though, in that it's a major pain to get to the nut meats, as hulls and shells both are made of titanium

But the biggest tree on the property here (and perhaps in this valley) is an ancient, giant white oak beside the house -- trunk at least 15 feet in circumference, easily a hundred feet tall, canopy covers a larger area than the roof of the house. That's a lot of acorns, and there's another full-size white oak in the front yard (probably a descendent of our giant). Mother Earth News says white oak acorns are lower in tannins, and thus much yummier, less bitter, than many others, so I'm happy.
We also have a good-sized black oak on the other side of the house. Those acorns will be bitter (high tannin content) but still edible. Also, if you boil them in a few changes of water, you can remove most of the tannins, and the first change of water, with high tannin concentartions, is a good remedy for insect bites, sunburn, etc.
Acorn flour, here I come.
[Edited to add link to Mother Earth News article]