Here’s something that Canadians will enjoy. If you buy an iPhone directly from Apple it actually comes unlocked (even the new iPhone 4). According the FAQ on their site:
“Why does the price of iPhone from the Apple Online Store differ from its price from a carrier?
Carriers typically sell the iPhone with a contract that subsidizes the initial purchase price of the phone. By purchasing your iPhone without a contract, you can use any SIM or micro-SIM card from a compatible carrier, including your current one.”