We're only a dozen years into the "future" of mobile telecommunications, and business travelers are already slamming up against a wall that is as old as Alexander Graham Bell.

As it was for landline calls and cellular calls before it, data roaming becomes a murky cesspool of extra fees the moment a business traveler crosses a national border. And the more we rely on our smartphones to keep us connected when we leave the country, the more we're confused by the bewildering prices and policies that the mobile-phone industry imposes.

"I'm going to scream if I read one more story complaining about a $25 fee to check a bag. Why do I care about $25 when I just got a $772 charge for using my iPhone in London for four days?" asks Elaine Marzo, a normally even-tempered sales executive for a Los Angeles apparel manufacturer.

Like many of her globetrotting compatriots, Marzo is physically, emotionally, professionally, and financially tethered to her phone when she travels. And she's shocked—shocked!—to learn that her go-to device is eating her out of metaphoric house and home whenever she travels overseas.

Tom McCallum, a business coach and former hospitality executive based in the Caribbean, may be even more annoyed than Marzo. He thought he'd prepared for the worst by purchasing an "unlimited" international data roaming package for his BlackBerry. But when he returned from 22 days on the road recently, he found a bill for $2,000 in data "overages." It turns out that his "unlimited" plan had been unilaterally revised by his mobile carrier. His usage had been capped at 1 gigabyte, and McCallum had used almost 3 gigabytes on his trip.

Before we go any further down the data roaming rabbit hole, though, let's back up to when the "future" of communications arrived for business travelers. Although it's impossible to pinpoint when most business-travel tools became "essential," we do know the exact moment when mobile devices became a must-have for traveling executives.

In May, 1998 the old AT&T Wireless rolled out a revolutionary program called Digital OneRate, and business travel was never the same. OneRate was stunning in its simplicity. For a flat fee of $89.99, you got a then-amazing 600 minutes of calling time. No roaming fees, no long-distance charges, no landline exceptions. One price covered any domestic call you could make or receive, anytime or anyplace. If you were a big talker, there were OneRate plans that included 1,000 ($119.99) or 1,400 minutes a month ($149.99) too.

Considering that the Internet was still a toy for nerds in 1998 and that many business travelers didn't yet have email, AT&T's flat-rate calling program was a classic example of disruptive innovation. Business travelers rushed out to get cell phones, and it wasn't long before using overpriced hotel phones and public pay phones were a thing of the past. The rest of America soon followed, and flat-rate mobile-calling plans became the industry's standard pricing model. Texting eventually became a flat-rate-priced item too.

But data is different—or at least the mobile carriers say it is. As our data consumption rates explode—thanks to higher-speed networks that permit streaming audio and video, photo and social-media sharing, high-quality Web surfing and a proliferation of apps—the major U.S. carriers have backed away from one-price-fits-all data roaming plans.

In the last year, the two largest mobile firms, Verizon Wireless and AT&T, have stopped selling unlimited data plans. Both now offer only "metered" plans. The more data you "eat," the more you pay. T-Mobile's "unlimited" data plans have a retro wrinkle. Go over a preset limit of "high speed" data consumption and T-Mobile will "throttle" (slow down) your transmission speeds. Sprint still offers truly unlimited data options, but that may soon change because the company will reportedly start selling iPhones next month. And when iPhones arrive, data consumption skyrockets.

But our domestic data dilemma pales in comparison to our overseas cost crisis. Just as international landline and mobile calls continue to be insanely overpriced compared to domestic rates, international data roaming prices are rapacious. Your mobile carrier will charge you about 2 cents a kilobit for data you use overseas. That sounds cheap, but it isn't. A text-only email is about 20 kilobits, which means you'll pay about 40 cents for every one you send or receive overseas. A modest webpage could be 180 kilobits, or about $3.60 each time you view one on your mobile device. One minute of streaming video consumes about 3 megabytes or about 3,000 kilobytes. That's $60 of international data roaming right there.

So what do you do to rein in your data costs when you travel outside the country? Here are some tips worth considering.