Where do you camp?
We can sum this up in one famous-to-us phrase: follow the Brown Signs. Bureau of Land Management Land, National Forests, Public Boat Ramps, River Accesses, Historical Markers, National Wildlife Refuges, State Forests, Scenic Overlooks, etc. We are not telling you that you're legally allowed to camp overnight (in many places you're technically supposed to have a permit) -- we're telling you these are many of the places we have camped.
Rest areas are also good possibilities. We've camped miserably a couple of times in a Wal Mart parking lot (think 24 hour bathroom -- it's difficult in urban areas to find enough woods to pee in). We have friends who have camped overnight in hospital parking lots and parking garages and community colleges and city parks.
Stay far, far away from airports (you might be a terrorist) and anywhere that has posted No Overnight Camping signs. No Camping is actually much more flexible than you think -- airports are not. We've been rousted twice in our tens of thousands of miles of traveling -- once in a Fishing Access area just outside Yellowstone, and once at a Scenic Overlook near the Anchorage Airport. Near Yellowstone the nice officer had this particular area on his route because local kids had been using this spot to drink and raise hell. He talked to us while we were cooking, long before we were obviously camping, and pointed us five miles up the road to a much, much nicer National Forest campground that was free and sheltered from the insane wind that developed later that night. In Anchorage we had driven and driven and driven around looking for a spot to camp. The guy roused us with all his lights flashing, banged his heavy flashlight against the van. The kind of cop that makes you think oink. Ah, well.
A word on campgrounds. Most expensive: a KOA-style campground is going to cost you at least 20 bucks -- as much as 45 in some areas, so avoid this unless you absolutely need their shower/laundry/wi-fi/pool/hot-tub/etc. Personally, I'd rather pay a little more and get a hotel. Least expensive: National Forest Campgrounds or BLM campgrounds, which average about $8. We have run into State Forest Campgrounds for as little as $3, but they've always been packed with folks, so we've never actually taken advantage of these. These less expensive campgrounds are typically more forested and primitve (we like primitive); facilities typically include fire pits, pit toilets and potable water. If you pick one with a lake or stream you can bathe with a biodegradable camp-soap. Love the earth, baby.
Once you pass out of the South or Midwest and into the West, you'll have no problem finding public land to camp on. I've been told by one researcher that Utah, for instance, is nearly 40% public land. Contrast this with Texas, who the same lady claims is less than 3% public land. With the exception of Malibu, the entire West Coast is really laid-back and will let you spend the night just about anywhere. These lands are your lands, these lands are my lands. Public lands mean a lot to us. Land should be held in reserve, as pristine as we can keep it. It's as important as reproductive rights and education.
Something else worth fighting the Republicans for.