Aiport 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.

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.

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).

•Baggage carousel advertising , a fast-growing trend, is coming to Seattle, Philadelphia and Boston Logan.

Operated by DoubleTake Marketing, it's comprised of a large adhesive graphic that's placed on the moving portion of the baggage carousel.

DoubleTake's ads are also found at Chicago O'Hare and Midway, Kansas City, Albany and Gulfport-Biloxi, Miss. Ad sizes range from 20-inch segments to an entire bag belt.

•Delta Air Lines and Air France/KLM have opened a co-branded lounge at London Heathrow's Terminal 4.

The two-level lounge, which is available for use by first-class and other elite customers of SkyTeam partner airlines, contains a spa, restaurant, day beds, massage chairs, wine bar, oxygen bar and an entertainment station with computer games. It also features an "indoor living wall" with more than 60 species of plants.

The lounge makes its debut less than a month after the Air France KLM Group and Delta announced a long-term joint venture in which they'll coordinate trans-Atlantic operations and share revenue and costs.

The airlines will cooperate on routes between North America and Africa, the Middle East and India, as well as on flights between Europe and Latin America.

•Kansas City International now offers valet parking. Customers using the service can pull up to a valet facility and leave the keys with an attendant. They are then driven to their gate by shuttle. An uncovered space costs $7 per day, and a covered space is priced at $11.