Tip: Text Alerts — Something Actually Free From the Airlines
Continental, for example, will both e-mail you a PDF of your boarding pass for a return flight (if you check in online for the first leg of the journey and select this option), and also alert you to delays and gate changes. Visit continental.com and sign up for alerts on the day of your flight. Once you confirm (by responding to the first text message), you'll get a welcome message.
Then, depending on what you've signed up for, you'll get alerts every 1, 2, 3 or more hours before flight time letting you know whether you're flight's on-time and what gate it's leaving from. Even if you know your flight's delayed, it's probably still prudent to head to the airport and check-in close to the originally scheduled time. But at least you may be prepared for a long wait. And in the case of major traffic disruptions, you'll know to contact the airline possibly even before getting to the airport.
For those heading out to the airport to pick up a passenger, check out Northwest's text alert program. You put in the flight number, and they'll let you know when the flight takes off, if it's running on schedule, when it touches down or reaches the gate or when it's expected if it's delayed.
All this means you can be out and about or on your way to a distant airport and text messages will keep you informed of your friend's progress instantly so you don't have to look it up or call the airline.
Combine airline alerts with the fact that passengers can make phone calls as soon as the plane's on the tarmac and soon there will be no excuse for arriving to pick someone up other than at the exact time the person emerges from the baggage claim area. That should cut down on the number of laps you have to make while hedging about whether you ought to have just parked and gone in to meet your friend.