(FORTUNE Magazine) – A few years ago, Mark Mobius, president of Templeton Emerging Markets, saw a sign for a brokerage in Botswana's capital city, Gaborone, and ambled in to ask where he could find the stock exchange. The broker at work told him he was already standing in it--the brokerage and the exchange are one and the same. "If a second broker comes to town, we'll have to move the exchange out of our office," explains Stockbrokers Botswana chief Rupert McCammon.

Despite the stock market's unprepossessing trading post, over the past few years foreigners have invested $65 million in the 12 companies listed on the Botswana exchange; their market capitalization totals $530 million. Mobius, for instance, has seen a comfortable 56% return on Sechaba, the beer and soft drink company he bought in 1994.

Unlike this small pioneer, larger emerging stock markets have become established fixtures of the investing mainstream: in 1986, $2 billion flowed into 28 emerging-market funds; by the end of last year, the numbers exploded to $136 billion in 1,450 funds, according to Micropal. During that time there has been a lot of buzz about Asia's and Latin America's heady emerging markets (and more recently, about the wave of currency devaluations in places like Thailand, the Philippines, and Indonesia).

What gets lost in the news, however, is that despite their far-flung locations and sometimes volatile economies, many of these "emerging markets" more closely resemble developed nations than banana republics. In order to handle the onslaught of global investors, their stock exchanges have become sophisticated, high-tech financial machines: Brazil, for example, has nearly 560 stocks listed, worth $283 billion; China has 640 listings, worth $180 billion; and South Korea has about 765 listings, worth $154 billion.

But the Botswanas of the world--the real emerging markets--hover below the international investing radar. These are the one-room stock exchanges, where a blackboard and a telephone are often the only tools of capitalism. With so much money flying around the globe, it's pretty enticing--yet risky--for places like Bhutan, Oman, Kazakhstan, and India's Jaipur to try their hands at setting up an exchange in the hope of becoming the next Chile or Singapore. (According to the International Finance Corp., since 1985 the number of emerging markets has tripled, to around 85.)

Witness the nascent setup in Bhutan, a tiny country nestled between China and India in the Himalayas that boasts a four-year-old, 11-company stock exchange in Thimphu. While just $1.4 million worth of stock was traded there last year, the country only moved from the barter system to hard currency in the 1960s. The exchange is a meaningful step toward attracting the money managers who trek to just such out-of-the-way locales for a first crack at buying tomorrow's blue chips at four times earnings.

Some of the exchanges are flourishing: Bhutan's market cap is up to $40 million, and Oman's returns so far this year are 62%. Others, like those in Kazakhstan and Jaipur, are less lucky: Competition from other local markets is fierce, and perhaps deadly.

Elizabeth Morrissey, a managing partner at Kleiman International Consultants, an emerging-markets research firm, believes that during the next ten years, Africa and Eastern Europe alone will deliver up yet another dozen brand-new markets. With so many launches coming, she says, "over the next three or four years even the boring fund managers will be buying into the Kazakhstans of the world."

As these fledgling stock exchanges mature, they will inevitably become computerized, digitized, routinized, and altogether sanitized in order to fit into the modern financial world. Here, then, are a few parting glances at a disappearing way of doing business.