The coinage is not my own; to my knowledge, it was coined by a friend of mine who used it in an offhand comment, and I and a few friends have picked it up as a useful expression in the past year or so. But a quick trip to Google reveals that it's an expression already in use, and I notice that the current top listing means pretty much the same thing I mean, as do many of the other folks saying it.
The Nation is a broad semi-coherent community of people committed to living weird lives. There are several strata, like cacophanists and burners and various sorts of perverts and people who look for occasions to dress up funny and on and on. If you're familiar with Freak Nation—if, for instance, you know that opening a RE/search or Charles Gatewood book, you're likely to see someone you know—then you're probably nodding with understanding about what I mean. If you've never encountered Freak Nation, I fear that its boundaries are mysterious from this description, which is fair since they are a bit slippery. (But then, if you don't recognize what I mean, who are you, and how did you find my blog?)
The main rhetorical purpose of Freak Nation in my usage is not so much to refer to the nation itself, but rather to refer to an individual's level of "citizenship" in it. A proper citizen of Freak Nation typically has a unique collection of a few different qualifying characteristics: a heavily tattoo'd belly dancer, a professional clown with a taste for orgies, a pagan mechanic who goes out in drag Friday nights, a painter racking up skills at circus school, and so forth. (Yes, I know real people answering to all of these descriptions.) And this is part of the way that Freak Nation coheres: the mechanic might not know the clown, but likely they have several acquaintances in common if they live in the same city ... and Freak Nation is heavily networked all across the country, thanks to cheap airfares, restless FN citizens, and the internet.
A "full-time" citizen of Freak Nation has slipped the surly bonds of ordinary society, like the full-time deadheads of yore, making their living tree sitting or performing Reiki or teaching yoga. One can be said to hold "dual citizenship:" project manager by day, goth go-go dancer by night. Or to be a resident alien ... or to live in America and spend long vacations in Freak Nation ... or to have friends in Freak Nation who you visit on a tourist visa ...