From MSNBC:

United Airlines on Monday doubled its fee for a second checked bag to $50, citing volatile fuel prices.  United, a unit of UAL Corp., said the $50 one-way fee would apply for tickets bought beginning Tuesday for travel beginning Nov. 10. in the U.S. or to or from Canada, Puerto Rico and the U.S. Virgin Islands.  Travelers in first or business classes, “Premier” frequent fliers, and active-duty military personnel traveling on orders will be exempt. United estimated the $50 fee would apply to about one out of seven customers.

Also, Denver-based Frontier Airlines charge $15 for the first checked bag starting Nov. 1.  This is in addition to the $25 currently charged for the second bag.

I still believe more scrutiny needs to be placed on carry-ons, since the normal reaction of most travelers will be to try avoid paying the extra fees and taking more as carry-on.  Chad’s Simple Rule would be :  If it has wheels and you are not an airline employee, it AIN’T a Carry-On!!!  A bag on wheels that is being pulled behind the passenger is not a carry-on, it is a roll-on.  Carry-ons should be limited to small bags that do not have wheels, and bags with wheels should be required to be checked.  Please appoint me Air Travel Rules Czar.

You have my vote!

I agree Chad......I’m really sick and tired of trying to explain this to passengers.  Since USAirways now charges for any checked bag, most passengers now ‘carry-on’.  Which is absolutely ridiculous!  I recent had to put a flight in a 20 min. inbound holding because the outbound flight (still at the gate at dept.) was processing 30 gate check bags at 10mins. prior!!!  People where do you think these bags go????  So basically....save the $$$ but get a hassle and a delayed flight.  I personally think airlines should have the authority to automatically check bags of those that show up 45mins or less prior to dept. and expect to chk in, get thru security and race for the gate.  Cuz you know they are definitely not going to be one of the first on the plane and will be one of those ‘gate chk bag’ people.

Ahhhh and those same ones with all their earthly possesions are the 1st ones that complain that the plane is late.

AMEN!!!

If the airlines would stop charging for bags, people wouldn’t have to carry on larger luggage.  Power to the people!

Since Southwest Airlines doesn’t charge for bags, I try to fly with them as much as possible. I absolutely hate having to pay to check my bags.  Unfortunately, I have paid to check bags a couple of times with US Airways and it bums me out every time.  On the other hand, I like to take direct flights and Southwest doesn’t always have direct flights to places I want to go, therefore I have to bite the bullet from time to time and pay to check my bags.

Shawn, I understand you must fly out of PHX alot, however, USAirways is not the ONLY carrier that charges.  I am not agreeing with the ‘checked bag charge’ but a survey thru Travelocity, shows 3 to 1 passengers would rather pay the check bag charge or carry instead of paying the increased airfare airlines would have had to charge to off-set the high rise in fuel.  What would you rather do....???  Pay $300.00 rt to LAS when last year it was $250.00 or a .00 (1st bag) bag fee???

I would LOVE to see a companion fee to the checked bag fee—a fee for ANY carry-on that is not a briefcase or purse.  Most passengers are rational consumers, so if they have to pay to check but not pay to carry on, they will carry on as much as possible.  This does not reduce the weight of baggage, it just moves it from the hold to the cabin. 
If I have the choice of spending $15 or $25 to check a bag or pay the same fee to take that bag in the cabin, the cabin/cargo hold distribution would even out again.

good luck with that one

As long as the airlines charge a fee to check bags and do not charge NOR restrict the carry-ons, passengers will take as much as they can get away with into the cabin. 
If the airlines want to maximize revenue by charging extra for baggage, they need to plug up the revenue leak—free luggage in the cabin.