Previously the only way to legally unlock your cell phone was to wait until your contract was over. Rogers has just announced though that as of March 28 you will be able to get your phone unlocked 90 days after you get it activated. This service can be performed at any Rogers corporate outlet and will be valid for its Fido and Chatr brands as well. Of course this service will not be free, it will set you back $50. Bell and Telus already offer this unlocking service for a cost of $75 and $35 respectively. The advantage of getting your phone unlocked is that when you travel to another country you can buy a SIM card for use in that country, this is usually much cheaper than paying roaming charges with your home carrier.
Source: iPhone in Canada