If you get to Canada often then there are two options:
# If you have AT&T then get the "AT&T Canada plan":http://www.wireless.att.com/learn/international/roaming/affordable-world-packages.jsp#4, they have a $4/month plan where roaming in Canada is $0.59 per minute and any calls from the US to Canada are $0.19/minute while and text messages to the US are $0.50 per message. You can turn this plan on or off, so essentially, if you do more than 10 minutes of calling at the $2/minute roaming rate, it makes sense to sign up. Only draw back is Canadians have to pay international rates to call you, but it is your phone number.
# According to "GeckoBeach":http://www.geckobeach.com/cellular/intro/pre-paid.php a prepaid account makes sense if ou are using 30-50 minutes of air time. The best plan for folks that are going to Whistler or skiing would be the "Rogers":http://www.rogers.com prepaid SIM with $100 prepay card. That's because all the other cards expire after 30 days and you lose the number whereas the $100 card lasts for 365 days. So perfect for the once a year trips to Canada. The airtime charges are incredibly "confusing":http://www.rogers.com/web/content/wireless-products/paygo_rates?content10=paygo_rates, but they are $0.25 for first five minutes a day and then $0.15 there after for calls to Canadian numbers and $0.66/minute for calls to US phones. So that means you should get a prepaid if you are going to call way more to Canadian numbers, otherwise, using the AT&T Canada plan makes more sense. In all cases, either plan is better than the rack rate $2/minute roaming that is really highway robbery. the big benefit of course is that you have a local 604 number so you feel like a local 🙂
# "Skype":http://www.skype.com/prices. Skype is the other way. If you pay $36, then you get free calling from your PC to any number in US and Canada and you get a $12 credit for calling to other cities. You also can get a SkypeIn number (so your PC has a phone number 🙂 for $36. A pretty good deal.
# "Maxroam":http://maxroam.com. "John":http://www.theludwigs.com pointed this one out to me. It is fantastic because you can have multiple phone numbers attached to the same SIM, so it solves the having a separate sim for a bunch of countries. It is $30 Euros and you get a phone number in the US and can add 50 numbers from China, Canada, Hong Kong, Japan. So for instance a call to the US is ).67 Euros or about $1, so it is more expensive. A call to Canada is about the same. So it is expensive but convenient.
For your data devices like a Blackberry or an iPhone:
# "BlackBerry International":http://www.wireless.att.com/learn/international/roaming/affordable-world-packages.jsp#3 is $64/month that gives you unilimited email in 140 countries for $70/month. This is only worth it for folks who are there for a week or so as the email traffic really adds up.
# "iPhone Global Data":http://www.wireless.att.com/learn/international/roaming/affordable-world-packages.jsp#iphone-international. This is $25/month for 20MB of usage in 3 countries including Canada, China, Australia and Hong Kong and India and most of Europe.