We

small-business

owners rely on cutting-edge tools from

Google

(GOOG) - Get Report

,

Microsoft

(MSFT) - Get Report

,

Research in Motion

(RIMM)

and

Apple

(AAPL) - Get Report

to make money domestically, but taking "cloud computing" and

mobile applications

abroad is another matter.

I tried some of these

applications

and services while traveling in Italy. Here's what works and what doesn't:

Beware the cloud:

So-called cloud computing, which allows entrepreneurs to rely on outside servers for tech services, isn't ready for international prime time.

Like many cost-conscious small businesses, my little digital world does most of its word processing, content management and scheduling through Web-based tools, such as Google Apps, LiquidPlanner and Microsoft Office Live. These systems work well internationally as long as you have access to a strong, secure network. The problem is that U.S. networks and their international cousins don't function optimally.

During my trip, wired and wireless connections worked on a room-by-room or corner-by-corner basis. Even though signal strength and data rates appeared to be strong, upload and download speeds varied enough to clutter the systems. Updates of server-based files -- say, on Google Apps -- were incomplete. And Web-based notifications for meetings and collaborative documents weren't stable. Critical notices about completed files and scheduled meetings didn't go through.

I got uneven results with international versions of American wireless data plans. For example,

T-Mobile's

business data service, which works well domestically, was slow and uneven in Italy.

If you rely on collaborative software to work, you will need to confirm anything important with a separate e-mail or telephone call. Phone service is excellent internationally. You might be up at all hours finessing the time differences, but this is the life you chose.

Beware of mobile apps:

I was shocked by the poor international performance of domestic Web-based applications on smart phones. I tested several business apps on a BlackBerry Storm and an iPod Touch. I couldn't do basic stuff like check Facebook, LinkedIn and Twitter reliably from these devices. Text messaging, my communication method of last resort, was also spotty.

And, worse, I couldn't rely on voice mail and dial-in systems. International phone tones seemed to mucked up domestic services by

Vonage Holdings

(VG) - Get Report

,

Verizon Communications

(VZ) - Get Report

and

AT&T

(T) - Get Report

. If you plan to run even the most basic mobile apps or use American voice mail, I recommend getting a phone that works in the country you're visiting. Those iPhone apps might not do much good while you're traveling overseas for business.

Learn to love international conference calling:

Conference companies have started offering international dial-in numbers. These lines enable international calls to be hosted as a series of low-cost local calls. My provider, Los Gatos, Calif.-based ZipDX, goes as far as to remember our call-in numbers. Multi-leg conference calls involving people in Arizona, Missouri, Maryland and Venice, Italy were clear, easy to build and cost few or no additional fees.

It was probably the only high-tech service that worked properly as I traveled.

Bottom line:

My team is planning trips to cover technology in Russia, India and Malaysia, but we will be careful about how we communicate. Just because you can call, surf the Web and send text messages around the globe, doesn't mean all your services will work as you expect.

Our parochial American technologies just won't allow it.

Jonathan Blum is an independent technology writer and analyst living in Westchester, N.Y. He has written for The Associated Press and Popular Science and appeared on FoxNews and The WB.