Coolness, as every high schooler knows, is one of those things that’s hard to define but easy to spot among one’s peers.

With cities, being cool depends in part on being economically robust and vibrant, but also on other qualities, such as having a vibrant art scene, good restaurants and interesting local music.

For various reasons, these days almost any city can become a cool city, converting itself from has been to hipness in a relative blink of the eye. It has something to do with the Internet economy, which has a hop, skip and a jump quality about it, alighting in strange places for hard to predict reasons.

I was in Fargo, ND recently, giving a talk on What is Design to the architectural department of North Dakota State University, and it seems to me that this small city is one of those places that has suddenly become “cool.”

Fargo, as most people know, is known to outsiders principally for giving title to the movie by the Coen brothers about murder and Scandinavian accents and very cold weather. Fargo, to the extent that it stood for anything in that movie, stood for cold and dreary white people sitting in bars with not much to do.

I found some of that in Fargo, which to me was a nice break from New York. But I also found little restaurants, a very chic “boutique-style” hotel, and smart people doing interesting work. Most of this came through the eyes of architecture students and professors, who impressed me with the solidness and creativity. Fargo, I could see, could be a pretty good place to live, even though it does get to be 20 below zero in the Winter. (Which global warming has eased, the locals tell me: it used to be 30 below zero.)

Why has this city on the plains ascended the ladder of coolness? Some luck, some planning. Located at the intersection of freight and river lines, the city has always been a hub of manufacturing and industry, some of which is still there. The city was founded around the railroad lines in the late 19th century.

Some of the city’s coolness rests on a local boy making good, a certain Douglas Burgum who was the owner of Great Plains Software – until Microsoft purchased it for $1.1 billion in 2001. Now a top executive at the Redmond company, Burgam is still located in Fargo – and he and his ex-wife Karen Burgum has put money into a number of interesting projects. Just to name two, his wife started the boutique Hotel Donaldson, where I stayed very comfortable, while Mr. Burgum gave the architecture school the money to renovate the old warehouse that is its new downtown center. www.ndsu.nodak.edu/arch/

Of course, it’s not all Burgum money that’s making Fargo. And I’m just giving you my quick impressions after a quick speaking trip. Still, when I’ve gone to cities that are experiencing a comeback, it’s sobering how often I get the impression that private money plays a major part in their resurgence. That’s the case in Chattanooga, where a lot of old Coca-Cola, New York Times and other money has played a part in the city’s betterment. www.metropolismag.com/cda/story.phpIn this country, with government less active than in Western Europe, it’s often left up to private people – rich ones – to carry out what is in effect urban policy and design.