They're everywhere here in the deep south of the USA. Just stick to the back roads and avoid the interstate highways and you'll find them easily enough. There's a lot of good southern home cooking (soul food) even in many of the gas stations on the state and county roads in this part of the world. Unfortunately, I'm allergic to pretty much everything they serve, but JtS loves it. Reminds him of the cooking back home in Newfoundland.

I found one of those old trailer diners from my father's home town (Framingham, Massachusettes) on display in the Henry Ford Museum in Dearborn, Michigan while we were staying up that way a couple of years ago (not operational, of course). I keep meaning to ask my dad if he ever ate there when he was growing up. They've got the Rosa Parks bus on display there, too.