Delta Air Lines is now offering paperless check-in at New York’s LaGuardia Airport to travelers flying within the U.S. on Delta and Delta Connection flights. Domestic passengers now have the option to use their Web-enabled mobile device to check-in within 24 hours of their departure and receive an electronic boarding pass. Passengers who download their boarding pass to a mobile device via delta.com can check bags at a baggage drop counter and proceed directly to security. As we reported last month, Continental Airlines allows paperless check-in at Houston, Boston, Newark and Washington D.C. and Northwest Airlines offers mobile check-in at Indianapolis.

A caveat to paperless boarding enthusiasts: make sure the airline has the correct frequent flyer information on file for you. If you do not earn credit for a flight, many airlines require you to mail in the original boarding pass, especially if you are trying to get miles credited from a partner flight. If you check-in with your mobile phone, you will not have a boarding pass to use as evidence of having flown and may have a difficult time getting flight credit if the miles don’t automatically post to your account.