Quote from Pabst:
Riskarb: I've heard the term contango for many years and never knew what it meant. Is the definition, "carry to expiration"?
Contango means that as you go further out the price of the contracts increases.
Backwardation is the opposite of contango. Usually happens when there's a shortage of commodity.
For example, if you look at silver futures then they are in contango: CBOT silver futures
And the copper futures at NYMEX are in backwardation: NYMEX copper (just select "I agree" at the bottom of the webpage and then look at the "most recent settle" column)