You can now receive an e-mail alert when an award seat becomes available on a route you're interested in flying. Search for airfare on Yapta.com and click "including award tickets" to begin tracking the flight. Yapta will automatically send e-mail alerts if either the price drops or a seat available for frequent-flier point redemption becomes available. The service is free and works for on Alaska Airlines, Continental, Delta, United, and U.S. Airways.
We've written about Yapta before because of its service that allows travelers to track airfare price drops even after the ticket has been purchased. Read our post "Get cash back when fares drop."
Fun fact: Yapta stands for Your Personal Travel Assistant.