If you head to the Marin Headlands at Bicentennial, you can enjoy a free campsite (3 spots) that overlooks san francisco, ca and the Golden Gate Bridge during night hikes.
Anyway, this campground is basically car camping and has several hammock locations. I brought a 3 inch memory foam pad, doubled over(it was queen size), a large queen down comforter, down pillows, and put it all inside my Hennessy Ultra-Lite Explorer up in the Cypress tree.
This setup is the most comfortable I have ever slept!
Try the campground - its Free! and hammock friendly!
Try the memory foam/down setup for car camping!