I would agree that the President's Choice phone cards sold at Loblaws Superstores are a great deal - we had read about them on these boards earlier this year and my parents used them when they were in South Carolina for in March of this year.
It saved them a fortune on long distance charges. It works out to 4.5 cents per minute, and there are no services charges or additional fees, other than the cost of purchasing the card (they come in $5, $10 or $20 amounts).