If you are traveling overseas and don't want to pay a ton of money for your cell calls, this column is for you. I got started down this path because of some upcoming speaking engagements in Australia in the new year, and I wanted to be prepared and be in touch. Soon, it turned into A Project, and now I share the results with you, my gentle readers, for your own benefit should you find yourself in similar straights.

You have the following alternatives

-- Buy a phone calling card once you get to your destination and use it from payphones or your hotel,

-- Don't do anything and use your existing US phone,

-- Buy a new SIM module for your existing phone, or

-- Buy a new SIM module and a new phone.

Why bother? If you have ever taken your cell to Canada (or even further a field), you know why: the per-minute cost for calls is ginormous. And while it is nice to be in touch when you travel around the world, there are lower-cost ways to do it. The calling card is a decent option, depending on where you are going and what your hotel charges for both toll-free and local calls. Some are still back in the profiteering stone ages and charge almost as much as the cell providers on a per-minute basis, even to make a local call or to connect to the calling card provider. You should know that some calling cards may not work with some pay phones, according to Dan Dern. He also reminds me that you might want to invest in a DMTF tone generator if you need to call back to a stateside answering machine - some foreign phones don't generate the correct touch tones.

The other options will only work if you have at least a tri-band phone on either T-Mobile or AT&T/Cingular networks. If you are using Verizon or Sprint, you need a new phone. Most of the world's cell phones (except in Japan and a few other places), work on what is called the GSM networks that operate at either 900 MHz or 1800 MHz. The US and Canada GSM networks operate at 850 MHz and 1900 MHz. So if you have a phone that can work on at least three of the four bands, you should be set to roam abroad. So we arrive at the last options, and here is where things get interesting.

Before I get any further, let me explain that your cell phone has two important pieces: one is the phone itself, and this makes a difference with the number of radio bands that it works on. But the second piece is the SIM card that is inside the phone, and if you are like most normal people you probably haven't given this little thing much thought - until now. This SIM card is what is used by the phone to store your address book and also gives your phone your inbound number and identity on the cell network. It is about the size of a microSD memory card. If you replace the SIM card that came with your phone with a card that works in the country you are visiting, you get several benefits.

First, you don't pay roaming charges for local in-country calls, although if you are calling back to the States, you will pay international long distance charges. Second, if people in-country are trying to reach you, they don't pay for the international calls either. (Some of the networks overseas have the more enlightened method of calling party pays, but we won't go there for now.) You also don't use any minutes on your American cell accounts, which can be good if you have a limited number of minutes - when you travel, you don't think about all the time you are on calls.

The trouble is if you are going to several different countries, then you need different SIMs and have to keep track of the numbers too. That gets onerous. So there is another solution: buy a SIM card from Maxroam.com. This Irish vendor offers a universal SIM that will work across the globe, and has lower per-minute rates no matter where you are. Plus, like the VOIP services, you can set up your number to automatically forward to a series of numbers, so that you can be more easily reached as you travel. You don't have to sign a contract, the SIMs are inexpensive (about $43), and you can add more minutes to your account easily over the Web and charge your credit card. It took me a few minutes to setup and activate the SIM online: you pick a US-based number for your phone, and pay for another number in the country or countries that you are visiting.

They have a wide selection. Each additional number is just a few dollars per month to maintain. There is just one catch. Chances are, your cell phone is locked to your carrier that you are currently using. This means if you try to take out your SIM card and replace it with this Maxroam card, your phone won't work. You might be able to receive calls, but not make outgoing calls. So how do you get your phone unlocked? You can pay for a special code that you enter and here is where things get dicey. Until recently, American cellular carriers claimed that unlocking was illegal. The laws are changing, but still many of the companies that provide this service have the feeling of going to the seedy side of town where goods are bought in cash through an open car window, not that I conduct my business in this fashion, you should know.

There are a number of unlocking providers, here are just a few and what they charge per phone to unlock:

Uniquephones.com $15

Gsmliberty.com $25

Cellularunlockcodes.com $20

Unlockexperts.co.uk $13

Cellularlocksmith.com $20

Cellphonerepair.org $25 I

have tried a few of these, and haven't had good experiences. All of them work by first charging your credit card the fee, and then sending you the code via email. Sometimes they take their sweet time in sending this code. Uniquephones "lost" my order, and only when I emailed their executives and spoke to them personally (they are based in the UK), did I get my code delivered. There are other services that have downloadable software, but that seems even more trouble. Once I got my code, it took seconds to enter it on my AT&T phone, and it was running on T-Mobile's network with my new number from the Maxroam folks. Sweet. You can also try calling AT&T or T-Mobile and seeing if they will give you the unlock code -- if you have had your phones or been a customer for a few years, this might work.

If you are reluctant to do business in this fashion, then you have another option, and that is to still buy the Maxroam SIM card but get a new phone that comes unlocked. If you are a Verizon or Sprint user, this is really your only option. There are many Web sites that offer to sell you unlocked models. The least expensive phones that I could find (that were at least a tri-band GSM model) were on TigerDirect.com - they were selling a Motorola V180 for $50. And Amazon.com has a Motorola V220 for $70. Neither of these phones are going to win any design awards, but they will do the job. Plan on taking a few weeks to negotiate all of these options, so don't do this a few days before you have to leave the country. And you might want to bring along your current SIM card, just in case.

David Strom is a noted speaker, author, podcaster and consultant who has written two books and thousands of magazine articles for dozens of IT publications such as Computerworld, eWeek, Information Week and Network Computing. His blog can be found at http://strominator.com, and he can be reached at david@strom.com