You’ve probably just about gotten used to the idea of paperless airline tickets, or e-tickets. But now paper boarding passes may be going out of use completely.

Here’s how it works: When you check in, instead of getting a piece of paper, your boarding pass will be emailed to your cell phone or PDA.

No need to print out a boarding pass from home or go to the kiosk in the airport.

You’ll still need identification, but the TSA can scan your bar code at the check point to get your name and flight information, right from your phone.

Right now Delta has them at LaGuardia, and will expand to three other cities.

Alaska Airlines uses them at Seattle-Tacoma.

Continental has expanded them from Houston to several other cities.

The TSA plans to expand paperless boarding passes throughout the U.S. in the next year.

This may sound like a bad plan if you don’t have a cell phone, but for now at least, paperless boarding passes are optional—you choose when you book your flight or use your mobile device to check in and retrieve the pass.

Learn more about the latest developments in air travel with our Airlines & Airports section.

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