(MONEY Magazine) – Long check-in lines will greet you at airports this summer, which is expected to be the busiest for air travel since 2001. But there are things you can do to speed you on your way. In the latest addition to the self-service wave sweeping the airline industry, you can check in for flights before you even get to the airport.

Most big U.S. airlines allow travelers to check in on their websites. You must have an electronic ticket (not a paper one) to use the service. Some airlines require you to enroll in their frequent-flier program as well.

Web check-in allows you to confirm flights, choose seats, record frequent-flier miles and print your bar-coded boarding pass up to 30 hours before takeoff, all from your home or office. If you have bags, you'll still have to check them, of course, but you can do it curbside or at express lanes set up for self-ticketers near ticket counters. Southwest passengers have another good reason to use the service: The airline doesn't give advance seat assignments, and early online check-in gives you a better shot at a coveted "group A" boarding pass so you're among the first in line to find a seat.

If you don't remember to check in online--or your slow dial-up service just makes it too frustrating--you can still save time by checking in at one of the stand-alone kiosks that airlines have rolled out in terminals. These ATM-like machines have been around for a while, but they're appearing in far greater numbers (see the table) now that they're catching on among savvy travelers. Again, you must use an e-ticket. At the airport you simply insert a credit card and use the touchscreen to check in and print your boarding pass.

You can do all of the Web check-in stuff at the kiosks, as well as request upgrades and put yourself on standby for another flight. Kiosks work even if you have luggage; typically, customer service agents assigned to the kiosks tag bags using nearby printers. And some airlines, including Northwest and United, offer discounted upgrades to business or first class if you use a kiosk.

Now, if only there were a way to speed through those airport security lines. --DONNA ROSATO