United Airlines and US Airways recently announced they will join American Airlines and start charging passengers to check a first bag. That means a lot more people will start packing a lot more stuff into their carry-on bags.
“Not so fast” say the airlines. They’re cracking down on over-sized carry-on bags by posting staff at the security checkpoint lines in an effort to ‘head ‘em off at the pass.’
Find out more in my Well-Mannered Traveler column on MSNBC.com. 
Starting today, May 5th, non-exempt travelers flying on Continental, Delta, Northwest, United and US Airways must pay $25 to check a second piece of luggage. American Airlines will begin charging that same $25 on May 12. Air Tran jumps in with a $10 second-bag fee on May 15th. And, just in time for summer travel, passengers on Alaska Airlines and Horizon Air will start paying that $25 fee on July 1st.
One bit of good news: As of today, United Airlines will waive that second bag fee for passengers who pay to check luggage at remote baggage check-in sites such as hotel lobbies, convention centers and cruise ships.
No word yet on how long the airline will be doing that, but so far it is the only airline to do so.
