While the debate over domestic data limits — 2GB versus 5GB versus truly unlimited — continues, another, more controversial smartphone bandwidth topic is slowly coming to a boil: international data. For those of you who frequently venture out of the confines of these United States, you know what we’re talking about. If you haven’t yet made your way out of the country in the smartphone era, you’re in for a rude awakening. Exorbitant costs, pathetic data allowances, and little recourse… it wasn’t always as bad as it is now. But, like all things in the cellular industry these days, carriers seem to be charging more for less. Are you the kind of person who always has your passport and smartphone with you when you travel abroad? Are you sick of being raked over the coals? Read on for our thoughts.

There was a time, about one-year ago, when international smartphone data plans were reasonable. But those days are now a thing of nostalgia. Once upon said time, if you were an AT&T, Sprint, T-Mobile, or Verizon customer, you could exchange your $30 unlimited domestic data plan for a $65 unlimited international plan. The delta on your wireless bill was roughly $35 and while this did not give you the ability to talk on the phone while overseas (cheaply anyway), it did allow you to email, browse the Web, and conduct your business using your smartphone’s data channel both here and abroad. Now if you happen to be a government or multinational corporation — or work for one — you’ll be pleased to know that these very reasonable data plan offerings are still available to you! If you are, however, like most of the wireless companies’ revenue-generating customers, a plain old individual account holder, you’re screwed.

Let’s review the current international data offerings from the U.S.’s four major wireless providers, starting with Verizon Wireless: If you happen to be traveling to the United States’ nearest neighbors, Canada and Mexico, Verizon has two data plan offerings for you. There is a 75MB per month plan that costs $30 or a 200MB per month plan that costs $100. If you are traveling to the Caribbean or Europe, the data caps shrink to 25MB and 70MB, but still cost $30 and $100 respectively. Traveling to South America, Africa, or Asia? Verizon will let you use your device at the pay-per-use rate of $20.48 per MB. That’s per megabyte. The information about Verizon’s consumer global roaming rates can be found here.

Next up is AT&T: AT&T often touts its international prowess based on the fact that its network and phones utilize the more worldly GSM technology. But that is where the good news begins and ends. Ma’ Bell offers a 20MB monthly plan for $24.99, 50MB for $59.99, 100MB for $119.99, and 200MB for $199.99. Pay-per-use rates range from $15 per MB in Canada to $19.50 per MB nearly everywhere else. AT&T’s global roaming rates can be found here.

How about the cost-friendly T-Mobile? T-Mobile is a bit kinder to globetrotters… sort of. T-Mo offers BlackBerry customers an unlimited international email option (if you also have an unlimited domestic data plan) for an additional $20 per month. This does not, however, cover Web browsing, Twittering, Facebooking, etc. Only data sent through a BIS/BES connection. Data that does not travel through BIS/BES connection (that’s all data for non-BlackBerry users) is billed at $10 per megabyte in Canada and $15 per megabyte elsewhere. That information can be found here and here.

Sprint, surprisingly, has one plan (for two very specific devices) that seems to be the most reasonable. If you are a Sprint customer with an international BlackBerry (that’s the Tour 9630 or Bold 9650) you can purchase an unlimited international data plan for $69.99 per month. All other users are relegated to the pay-per-use model that varies depending on which country you’re visiting. Canada is listed at $2 per MB while Spain is listed at $16 per MB. We had to directly call Sprint to learn about the $70 BlackBerry plan (we couldn’t find it anywhere on the website), but the pay-per-use rates can be found here.

Again, all four major U.S. wireless carriers had an unlimited international data-plan offering for just $65 per month one year ago.

So if you’re a consumer or a small or medium business without a special, pre-negotiated wireless contract, those are your options. And aside from one attractive BlackBerry offering from one carrier, none of them are very good. What’s befuddling and maddening is why wireless companies continue to favor big businesses. Sure they travel more, but when did an enterprise electron traveling over a wire become so much cheaper than a consumer electron traveling over the very same wire? Today, T-Mobile published a press release touting an “80% discount” on international voice and data for “multinational corporations, government agencies and U.S. enterprises.” But my question is why? Why does the data used by a corporation, discounted at 80%, remain profitable while consumers pay an 80% premium? Are we subsidizing big businesses or are we just getting screwed? Those seem to be the only two options I can think of.

Wireless companies are scrambling to find a delicate data balance — for both domestic and international plans — that will bring ultimate profitability while inflicting a sustainable amount of consumer pain. I just wish one wireless company, nay, any wireless company, would take the high road and offer some legitimate, value-based choices. That would be great, and that would be a company I could stay loyal to.