You may want to leave certain aspects of your life behind when travelling somewhere, but your cell phone or smartphone may not be one of them. The only problem is that using up your airtime and data while away can lead to some massive phone bills.

But there are a couple of Canadian alternatives that can really help you avoid paying more than you should when roaming and calling long distance. Based in Mississauga, ON, a suburb of Toronto, Roadpost provides cell phone users with more affordable airtime and roaming rates on contract-free monthly plans. The company makes its own SIM cards, which are the small thumbnail-sized cards that work with phones using the GSM (Global System for Mobile communications) network. In Canada, Rogers and Fido are the two carriers that operate on GSM, and most of the world uses the same network as well.

Roadpost's SIM cards are designed specifically for travellers from Canada and the U.S., regardless of whether they're going for business or pleasure. The company offers cards for up to 200 countries, although a majority of those fall under Raodpost's World SIM card. There are individual SIM cards for Australia, Britain, China, France, Germany, Greece, Italy, the Netherlands, Switzerland and the U.S.

Here's an example of how it works. Let's say you're travelling to China and you want to use a cell phone while you're there. If you were to make and take calls with your phone under Rogers or Fido, you'd easily be paying more than $3.00 per minute when long distance and roaming come into effect. With Roadpost's Chinese SIM card, that rate plummets to $0.45 per minute, which is an almost 90 per cent savings.

Though incoming calls with the China SIM incur the $0.45-per-minute cost, most of the other country-specific SIM cards offer free incoming calls to add to the overall savings. Unfortunately, the U.S. one isn't part of that group.

The U.S. SIM card works on AT&T's and T-Mobile's network and it costs $0.29 per minute to make calls to American landline and mobile numbers, while calls to Canada are $0.49 per minute. That's a noticeable 70 per cent reduction from what Canadian carriers would charge. Calling Canada with a Rogers, Bell or Telus phone would be as much as $1.70 per minute. Calls within the U.S. are as much as $0.95 per minute.

There is also Roadpost Connect, which is a North American cell phone number that can be tied to the overseas number attached to your Roadpost SIM card. This makes it easier for friends and family to call you while you're away.

Each SIM card will cost $29.99 plus shipping, which typically takes two business days. They can even bundle in a cell phone for a starting price of $49.99, though don't expect anything too fancy in the selection. Airtime can be paid for on a pay-as-you-go basis or you can opt for a bill each month you use the phone. Charges will show up on your credit card but Roadpost does send you a detailed statement of all your calls.

If you need BlackBerry data to go with your airtime, it will cost $0.01 per kilobyte, which isn't bad, but can also add up if you're not careful.

Despite the wide coverage over 200 countries, they don't all translate to any savings because the real cost-reductions come from agreements Roadpost has with carriers in other countries. This is why a World SIM card isn't all that effective in countries as varied as Japan, Cuba, Egypt, Croatia, Thailand and Ghana. In some cases, it would make more sense to just purchase a SIM card from one of the country's local carriers. Roadpost offers a way to search for costs and savings by country. 

Another option worth checking out, though I haven't tried it myself, is Montreal-based SIMPhoneE. They offer services very similar to Roadpost's that are also competitive in pricing.

Between these two services, you should be able to enjoy your trip abroad and avoid the annoyance of having to pay exorbitant fees when you don't need to.