One of an international traveler's concerns is how to call family and business colleagues back home in the U.S. Inflated hotel phone rates can break the bank, so it's worth investigating alternative channels of communication.

Here are two that can be mastered even by the low-techies among us.

Cell phones, called mobile phones overseas, are popular with globetrotters. Check with your phone service provider before you travel to determine the type of phone you have and whether it will work at your destination. Renting a cell phone with a new number for your journey is costly and inefficient, as your callers from home will incur long-distance charges on their landlines as well as on their cells.

A GSM (Global Systems for Mobile communications) phone is the most widely used — 99 percent of all countries — cell-phone network on the planet, incompatible with the U.S. CDMA (Code Division Multiple Access) network. The largest GSM service providers in the U.S. are AT&T (which absorbed Cingular) and T-Mobile. GSM phones will work in Mexico, Canada, Europe, Australia, Africa, most of Asia and aboard many cruise ships. Since South America coverage can be iffy, check with your provider first. Further, you'll need to request that your phone be activated for "international roaming" or international long distance. Service providers may impose usage restrictions on new customers until a satisfactory payment history is established.

A quad-band-frequency phone allows you to roam almost anywhere globally. It covers the 850 MHz, 900 MHz, 1800 MHz and 1900 MHz frequency ranges. Many countries in South America only have 850 MHz GSM service while both 1900 MHz and 850 MHz GSM services are supported in the USA. Your GSM phone assumes the characteristics of the wireless network in each country you visit. Most phones are preset to roam automatically, which means that the phone will switch networks as you move from one country to another.

Using your cell to make and receive calls abroad is not cheap, but it certainly is more convenient than finding local payphones or phone cards and less expensive than calling from your hotel landline. AT&T, for example, with service to and from more than 195 countries, offers standard international roaming rates, plus discounted rates for 85 countries to customers signed up for its World Traveler plan, at $5.99 per month. To give you a measure of cost, its rates per minute to/from South Africa are currently $2.49 or $1.69; Hong Kong, $2.29 or $1.99; and most cruise ships, $2.49 (a huge savings over the $6.50 to $9.50-plus charged by the cruise lines).

You can use text messaging on a regular cell and check your e-mail on a data-enabled phone like BlackBerry or iPhone. You'll pay about 50 cents per text message sent and up to $20 for a large 1 MB e-mail with attachments and photos.

For the technologically-savvy overseas traveler, a worldwide SIM (Subscriber Identity Module) card — portable memory chip — could be a better and cheaper solution for staying in touch. A SIM card, that you insert into your regular cell phone, contains information about its phone number and can be programmed with a prepaid number of minutes of use. A global-roaming SIM card will provide you with a permanent phone number for worldwide use. As your phone must be "unlocked" if it is locked in to only one network, check with your service provider to determine the status of your phone.

SIM cards require no contracts and no connection fees, and some offer free incoming calls to specific countries. Investigate significant phone savings offered by well-reputed vendors of worldwide (up to 170 countries in most cases) SIM cards like Blue Fire Wireless at www.bluefirewireless.com and Mobal at www.mobalrental.com/gsm/sim.asp.

If saving money on domestic long distance or international calls is of primary importance, look to Voice Over Internet Protocol (VoIP). This technology digitizes your voice and sends it via the Internet to the other caller, who hears it on his PC's speakers or by routing it through telephone lines to anyone's standard phone line. The major service providers for VoIP calls are Skype, www.skype.com, and Vonage, www.vonage.com. Using VoIP while abroad is probably the cheapest way to stay in voice contact if you'll be close to high-speed data lines. A call on Skype, for instance, to a U.S. landline anywhere in the world is only 2.5 cents a minute. Even better, calls between Skype members are free. Travelers can make calls using their VoIP accounts from any computer with high-speed Internet access that has the correct software.

Another plus is that you don't actually need to use a computer to utilize VoIP. If you have a Smartphone or phone with Windows Mobile, you can download Skype to it and make VoIP calls whenever you are connected to a WiFi network. Apple iPhone users are less fortunate for now: Apple doesn't allow third-party applications on its phone. The quality of VoIP is reported to be equivalent to using a cell phone. The right phone works with any open WiFi network and with secured networks to which you have access.

With Vonage, for example, you will typically need a broadband phone adapter or specialized software for your laptop. When traveling, plug the adapter into an Internet connection, then plug into the adaptor the standard landline phone you've brought along, and you can make calls as though you were back home.

If you want to know where to use your cell phone at a particular destination, JiWire, www.jiwire.com, has a listing of more than 220,000 free and paid WiFi hot spots in 135 countries. To find Internet cafes, check www.cybercafes.com, with a database of more than 4,200 in 141 countries, or look into World66, www.world66.com.

Irene Croft Jr. of Kailua, Kona, is a travel writer and 40-year veteran globetrotter. Her column is published in this section every other week.