score:7
That's a lot of questions, son.
The cheapest way to stay in touch with your family is to install Skype or an equivalent service on your phone, and then call from some place with wifi. If you both use Skype, it's absolutely free even for video calls; if you use Skype to call their mobile or landline phone, you'll pay a few cents per minute. Just be sure to use wifi, not roaming, or the data costs will be murderous!
Here's the basic logic: since it's you who's roaming (= in a different country), you pay all the extra charges if somebody calls you or you call someone. In other words, if your family calls or texts you, they pay for the call/text to Canada (because that's where your number is), and Bell will then charge you for forwarding the call/text to the US at some astronomical rate.
If you get a US SIM card, you now have a new number in the US. (And since your old SIM card is no longer in the same phone, it's now unreachable; you need to tell everybody your new number. Of course you can always swap it back when you return.) If your family calls/texts your new US number, they pay the cost of the international call; if you call out to Canada, you pay.
One catch: you need to ensure that your phone is "unlocked", so it's allowed to change SIMs. Call up your operator and ask.
There's absolutely no point in getting a new phone, all you need is the SIM. I'm currently visiting the US and have been reasonably happy with AT&T's goPhone (link to random but informative blog post), which you can get set up for $20 or so, although you'll probably want to pay $25 extra for 1 GB of data.
Then a major caveat at the end: the above is how things work in 99% of the world. The US, Canada and other NANPA countries are kind of messed up, since they share the same country code and they don't distinguish between mobile and landline numbers, making it generally impossible to figure out where any given phone number is actually located and thus complicating the normal logic of "caller pays only for where they think they are calling"... so while you're guaranteed to get reamed if you roam anywhere in the world, in the US/Canada/NANPA it's possible that people calling you get reamed as well. Yay for telcos!
Upvote:4
Definitely avoid the roaming fees.
Buying a US SIM card is in my view the most convenient.
You will need to have your phone unlocked if it isn't already.
With Bell Canada there is reportedly a charge of CA$75 for unlocking (source). There are numerous services online that will do this for you for cheaper. Here's one example: http://www.unlockallcellular.com/
The only real downside to getting a new phone numbers is that you will need to give your family this new number to ring while you are abroad. I would recommend buying your SIM card before you go to the US so that you can have a number to give people before you go and also so that you don't waste time looking around while you're in the US. That can be done through any one of a number of resellers or there are some good deals on eBay for prepaid SIM cards too.
@jpatokal already mentioned the possibility of using Skype, which is good except for the fact that you'll be needing to find WiFi to be able to make/receive any calls. You could try to work around this by just buying a SIM card with only data and no call credit. Then use that data to make/receive calls through Skype. You could even set up a Skype incoming number so they can call from a normal phone line. Extra costs would apply to do that course.