When it comes to smartphone usage while abroad, there are so many possibilities for ruining your vacation.

Let me count the ways:

Perhaps you'll find that your cellphone won't work at all because it doesn't support the international 900 MHz and 1800 MHz frequency bands, and you'll be unable to communicate with friends and family back home.

If you failed to have your cellphone carrier unlock your phone before you departed, you can spend hours of your precious vacation time trying to find a place that sells or rents phones, or offers phone kits with SIM cards to liberate your calling capabilities.

But no one wants to return and find out that all of those roaming and data charges have inflated your wireless bill to record levels.

So how should you handle it all?

If you plan on taking a very short trip and will keep your calling and data usage to a bare minimum, then you can use your current GSM phone from your wireless carrier and ask about international calling plans.

But your charges will mount in a big hurry if you aren't super-disciplined. If you're using a smartphone, one of the most effective means of saving money is placing the phone into "airplane mode," which gives you offline access to all your programs and apps without the cellular connections that will take a chunk out of your bank account.

Prepaid SIM cards are attractive options if you are staying for an extended period of time in one country, says Ken Grunski, president of telecom services provider Telestial (

One key advantage of prepaid SIM cards, which can usually be purchased from $17 to $80, is that your incoming calls will be free. And you'll be able to avoid those pesky and substantial international roaming rates if you purchase international roaming SIM cards, which work in multiple countries.

"In the UK, for example, the experience is quite straightforward," Grunski says. "Everyone speaks English. Just pop into a shop that sells SIM cards, which cost £5-20 and you're in business."

But watch out if your itinerary hits several destinations.

"If you go to Dublin, just make sure to buy another SIM card; otherwise you are roaming," Grunski cautions.

SIM cards cost about €5-10 in France, and you'll have to purchase them at mobile phone stores, Grunski says. You can also find them, along with traditional calling cards, at most tabacs. There will be various tariffs, and the voice prompts to set it all up likely will be in French so it might not be a simple process if you are jet-lagged, Grunski says.

In Italy, expect a SIM card to cost €5 to 10 as well. There is a somewhat cumbersome registration process, he says.

Of course, Telestial -- and others -- offer prepaid SIM cards and roaming SIM cards which generally cost more money than those you can purchase once you reach your destination. But one convenient factor is that you'll know what your new cellphone number is before you depart so your cohorts will be able to track you down -- if you want them to.

Grunski has some additional tips.

Realize the limitations of Wi-Fi while traveling. It may not be available in many places and, if it is, there may be fees.

Also, make sure you turn off your data apps on your phone or other mobile device. "Those jokes of the day and weather updates are not free and could be costly," Grunski says.

And that would be no joke.

Dennis Schaal covers travel tech as North America Editor of Tnooz (, and co-authors USA Today's Digital Traveler column.