OK, I've searched the forums for plenty of other DIY hammock stand designs. I realize that most people have focused on making them portable.
What's wrong with the idea of just cementing a pair of 10 foot long 4x4s into the ground? Bury them about 2.5 feet, cement them in, and maybe attach a couple of eye bolts to the top.
4x4s come readily in 8, 10, 12 ft increments for about $15-$30. With concrete, this could be a fairly inexpensive setup.
My only questions:
1. Will I need some sort of top beam. I imagine that the hammock will tend to pull the 2 beams together. Perhaps even a section of pipe.
2. How far apart should the posts be? I'm guessing about 14 feet or so.