Update - Thanks to reader Sharon in Saskatchewan for trying this out and confirming that it does, indeed, work in Canada!

Today Google is rolling out a new feature to Gmail that will allow US-based users to use Gmail's Chat feature to dial out to cell phones. As long as you have a computer or laptop with an active microphone and speakers, you will be able to use the internet to place a call and carry on a conversation with anyone using a cell phone. Calls made this way within the United States and Canada are free, however there's a slight twist for Canadians. Technically the service is only for US users at the moment, but Google Canada is under the impression that as long as your Gmail settings are set to "English-US" the service should accept you. The update is being rolled out to users slowly this week. Some people will see it right away, others will have to wait. Right now I'm waiting so can't confirm if this will work in Canada. If it does, this is how you can use it.

First, you'll need to install the voice and video chat plugin. Once done you can then look at the contents list under the Chat section of the main Gmail window. It's the lower left-hand side. If you have the update you should now see the option "Call phone" under the contacts on your list where phone numbers are included. Clicking on that option will bring up a dial window with a keypad and you simply use it just like a regular phone. You simply speak into your microphone and listen to the response through your speakers. 

Google will allow you to place calls outside of Canada and the US, but you'll be charged for the service and will need to set up an account.

If this works, then it could end up being a very useful service for students living on-campus and are looking for a cheap way to stay connected back home.