Airport Check-in: More e-board; carousel ads make the rounds –

The use of electronic boarding passes, embraced only by a few tech-savvy travelers a year ago, is spreading rapidly.

American Airlines (AMR) has expanded its e-boarding pass program to customers departing from Las Vegas McCarran, Atlanta Hartsfield and Minneapolis-St. Paul.

Customers can download their bar-coded boarding passes from the airline’s website to their Web-enabled smartphones and proceed directly to security, where screeners scan the phone to match the ID.

Delta (DAL) has also recently introduced the service for domestic customers departing from Salt Lake City.

Its service is also available at Atlanta, Las Vegas, Memphis and Minneapolis-St. Paul; Detroit and Indianapolis (Northwest only); and New York-LaGuardia (Delta only).