Due to Hurricane Fay, most of the major U.S. airlines are waiving change fees for passengers scheduled to fly to or from Florida airports (and in a few instances the Bahamas and the Caribbean) over the next several days. Some carriers, including Allegiant and USA3000, have canceled all August 19 flights from certain Florida airports. In both cases, flights have been rescheduled for the following day.
American, AirTran, Continental, Delta, JetBlue, Northwest, Southwest, Spirit, United, and US Airways are allowing passengers to change flights originally scheduled to depart August 19—and in some cases August 20, 21, 22, 23, and 24—to other dates later this week and next week for no charge. Normally, passengers must pay a fee of $50 to $150 to change flights.
If you think your flight might be affected, go to the airline's website and carefully read over its travel advisory rules (usually linked to on the homepage) to see if your flight qualifies for the change-fee waiver. You'll have to call the airline to rebook.
For more tips, read the Hurricane-Season Travel section of SmarterTravel.com's new Wiki.