As online audio goes "wireless" with the podcast, Myke Weiskopf looks back to the skies.

Five hours east of Greenwich, over a coastal city hemmed in by harbor islands, the sun sets a low flame just below the horizon-line. The outer edges of the landscape are burnished to an Indian-summer red by solar glare. Street lamps slowly constellate the foreground as a dormant radio frequency flickers to life, warm with transmitter hum. Fragments of a small folk tune cycle into an ionosphere-encrusted orchestral fanfare, and a disembodied announcer intones, "This is the Voice of... You are tuned... Our transmission now begins to..."

This is the great romance of shortwave radio, an all-encompassing experience that embraces geography, culture, trans-continental intrigue, and a sound world at turns both intimate and alien. For many, as a day-to-day means of experiencing radio, it has faded quietly into obscurity: a quaint, sepia-tinged cultural anomaly. Rather than swim against drifting signals through crosscurrents of dissonance, modern listeners have an array of simpler, cleaner alternatives by which to obtain their information. But despite the subsequent advent of everything from television to satellite radio, shortwave continues to draw a comparatively modest, but still growing, listenership.

Shortwave radios continue to do brisk business in the United States. An informal figure puts American sales around one million radios annually, adding to a wide-margin estimate of between 500 and 600 million shortwave radios extant worldwide. Sales predictably jump in times of global or regional flux, such as the Gulf War, the wars in Afghanistan and Iraq, and natural disasters such as the Sumatra-Andaman earthquake and Hurricane Katrina. Increased interest in international listening during these times could be attributed to a basic human desire for connection in times of distress, but the most salient reason may simply be the most practical: Try streaming your news broadcasts via the BBC Online during a power outage, or tuning into CNN when cable lines have been struck. Though shortwave may not always be "on demand" (to co-opt the mantra of so much digital media), it at least bears the distinct advantage of always being on.

Americans have a reputation for being creatures of convenience, though, and outside of those occasions when a collateral link to the outside world becomes a necessity; domestic consumers are being tempted by ever-newer and shinier vehicles. The media world at large has seen its share of "next-best-things," whether it is HDTV or MP3, and the trend continues apace in radio. In 2004, podcasting arrived on a jet stream of Internet-propelled hype, bearing the promise of radiophonic democracy to the village voiceless. Immune to commercial disruptions, geographical hindrances, or pesky ideological shifts, podcasting has been marketed as "public radio" in the truest possible sense, as it offers the opportunity for listeners to become broadcasters unto themselves. Harnessed to the ubiquity of the Internet, podcasting (they say) has the potential to reach exponentially greater numbers of listeners than any terrestrial station can manage, at little to no cost, in easily-digestible packets of instant programming.

If podcasting is like an express train to the heart of downtown -- sleek, accessible, egalitarian, then shortwave is like driving randomly all over the Eastern Seaboard, with the vague notion that it might be nice to end up downtown sometime next week. Podcasting is a means to a relatively defined programmatic end; shortwave listening, at its dark, mysterious heart, is all about the journey. Shortwave takes Marshall MacLuhan's hoary old cliché about the medium and the message to breathtaking extremes. A friend of mine once likened the medium to a "musical chance engine," in which the combination of ionospheric conditions, listening times, transmitter proximity, frequency crosstalk, and geography could produce radically different experiences between listeners. And, technically speaking, it can be a challenge: shortwave schedules can change from hour to hour and night to night; stations come and go in different languages, switching broadcast sites and target areas; a perfectly clear sky can be ruined by an ionospheric storm or auroral activity. Shortwave radio is eminently unreliable from one perspective, but wondrously unpredictable from another.

For reasons that go far beyond mere content -- beyond the Qu'ran chants, Russian piano ballads, Bulgarian vocal folksong, Indian film music swathed in shifting layers of cottony noise -- shortwave remains an under-explored alternative for radio listeners with the right balance of adventurousness, patience, imagination, and an appreciation for the inexplicable. Shortwave is a tactile pleasure, a dose of "old-world magic," in the words of philosopher Roger-Pol Droit. It is the sound of aboriginal tongues turning and adjoining, signals crumbling like loose earth as they traverse borders beyond the reach of any fiber-optic cable or WiFi relay path. It is the sound of clandestine revolutionaries in Mexico, livestock reports from Norway, Russian faith healers, morning weather in Kyoto. It is the sound of something irreplaceable by newer technology -- the sound, in short, of romance.

Myke Weiskopf is a 28-year-old radio artist, experimental composer, and "shortwave avatar." He lives in Cambridge, MA.