In Canada, if you hold a platinum (I think) Aeroplan American Express card, this gives you access to Maple Leaf Lounges. The card costs about $400 a year I believe and is affiliated with Air Canada's Aeroplan scheme where you can also earn miles when using the card for purchases.
You can also use the lounges if you are a gold card Star Alliance member or have an executive class (ie business class) ticket for an Air Canada / Star Alliance flight.