Many times you'll find free recipe offers on the can. Spam is a great example. If you look on the back of the can, you'll frequently see a free offer for a cookbook with several recipes that will help you make the most of this canned meat delight. Spend a little time sending in for these free offers. They might help you be creative when hard times arrive.
Canned margarine is harder to find.
Margarine in the tub will last a long time even unrefrigerated. It ordinarily separates into its components when it's not refrigerated. Just mix it up as it separates and try to keep it as cool as possible. Since Y2K will be coming in the winter months, you probably won't have a problem storing this food. Velveeta heated and mixed with a little water and powdered milk makes a reasonable butter substitute.