Most airlines offer text message, automated phone call alerts, and e-mail messages to alert you to changes in the status of your flight. Sadly, most of these services are horrible, only offering you the information once it's too late to do anything about the change or delay. If you want more accurate and timely flight status updates, sign up for alerts at FlightStats.com. Their updates are more detailed than those from the airlines and they are sent out in a more timely manner. They also offer real-time status of airports that are experiencing delays so that even if your flight is not listed as delayed (yet), you'll know if the chances are high that delays will be in your future.