Soon In-Flight Box Office will be offering an unusual - and unnecessary? - service for New York-bound travelers. People who didn't buy their Broadway tickets in advance, and don't want to go looking for tickets on the ground, will be able to purchase Broadway tickets right there on the airplane from flight attendants equipped with special handheld devices for processing Broadway ticket orders. The "pilot" run for this service will likely be tested on American Airlines, and the only Broadway shows that will be offered are Chicago, Mamma Mia, Spamalot, and The Phantom of the Opera. Presumably a wider variety of Broadway tickets will be offered on more airlines if there is sufficient interest.