Cell phone service for Canada -> U.S. if no sim card?

Once again here in Canada we pay the most fees in the civilized world for cell phones. You might be able to set your phone up in the U.S. to use here but as others have said it might be easier to use a computer. There are lots of free wifi locations within the cities.
The three main cell providers here do not want any competition and have convinced our Government that any U.S. providers would be bad for them.