The airline industry is profitable again, thanks in no small part to the billions of dollars in fees it collects from passengers every year. And it’s not just reservation change fees ($2.3 billion), checked baggage ($2.7 billion) and “miscellaneous” fees (almost $3 billion) that air travelers shelled out in 2009; now carriers are getting even more creative with their charges, imposing them for everything from redeeming frequent flier miles to carrying a bag on the plane.

Worse, the extras often come as a complete surprise, revealed only at the end of the purchase — and in some cases, not until a passenger arrives at the airport.

You want to check a bag? That’ll be $25. Need a confirmed seat reservation? Twenty bucks, please. An in-flight meal? Here’s the menu — we only take credit cards.

A new survey of air travelers found that two-thirds of respondents said they had been broadsided at the airport by unexpected charges. “Airlines have become addicted to fees,” says Charles Leocha, president of the Consumer Travel Alliance, a Washington-based organization that conducted the poll. So his organization has teamed up with a coalition of other travel groups, including the American Society of Travel Agents and Business Travel Coalition, to do something about it. They’ve launched a site, Mad As Hell About Hidden Fees and are pushing the government to tighten rules about fee disclosure.

But why wait for a law to be passed? Here are some of the newest, and most egregious, airline fees and how to escape them on your next flight.

Carry-on baggage fee
Who charges it: Spirit Airlines
How much: $30 online, $45 at the gate

Last month, Spirit Airlines, a small, Fort Lauderdale-based carrier that operates in the Northeast and Caribbean, shocked air travelers when it introduced a carry-on fee. Its chief executive, Ben Baldanza, said the fee would offer air travelers more options, and that “the basis for this new fee was founded in improved customer service.” Baldanza noted that it takes time to adjust to new fees, but was confident that passengers would come around to them eventually. “Long ago people would have thought that restaurants would cross a line if they asked customers to clean their own table,” he said. “Yet millions of customers do this every day at McDonalds and other fast food places.” There’s no word on how profitable the carry-on charges have been for Spirit. A spokeswoman for Spirit today said the fee was “going well.”

How to escape the fee: Downsize your carry-on. Anything smaller than 16 x 14 x 12, like a purse or computer bag, that can fit under your airline seat, is still free on Spirit. If you can’t, there are still a lot of other airlines to choose from that haven’t added this fee – yet.

Priority boarding fee
Who charges it: American Airlines, Southwest Airlines, others
How much: $9+

Before airline executives discovered they could make more money by selling priority boarding, you could count on embarking in a predictable order: People with special needs, families with young children, first class and frequent fliers, followed by everyone else. But now you can pay a little extra and move to the front of the line. The latest airline to charge for early boarding is American, which will give you Group 1 general boarding privileges and several other benefits, including a reduced change fee for tickets, for a fee. Asked about the success of the program, which was introduced earlier this summer, an airline spokesman said the numbers were “proprietary.” Southwest Airlines offers a similar “Early Bird” program that gives you priority boarding. The question is, what happens if a program like this really catches on, and everyone wants to board first? Will it just become a boarding fee?

How to escape the fee: Some passengers, including those who purchased full-fare or business class tickets, or who have elite frequent-flier program status still get priority boarding without paying the fee. Also, checking in as close to 24 hours before your departure will ensure a higher boarding position on Southwest at no extra charge.

A fee for the best economy class seats
Who charges it: American Airlines and other major airlines
How much: $19 to $39

The best economy class seats on a plane used to be a closely guarded secret known only to frequent fliers, and they’d reserve them at no additional cost. Those days are long gone. Many of the major airlines now charge for the coveted seats, even if they’re in economy class. The latest airline to sell the seats – you guessed it, American Airlines — makes these prized seat assignments available just before the flight leaves, at a cost. “Express Seats” are designated as the first few rows of coach, including the highly desirable bulkhead seats. Not to be outdone, United Airlines has several rows in the front of the plane designated Economy “Plus” that cost extra. They have about as much legroom as economy class seats did a generation ago, which for many passengers, is almost enough.

How to escape the fee: You can’t. If it’s not a full flight, and you can wait, there’s nothing stopping you from moving into a better seat enroute – subject to your crew’s approval, of course. But if you need a guarantee of a better seat, you’ll have to pay.

A co-pay for redeeming award seats
Who charges it: Most of the major airlines
How much: up to $500

The idea behind frequent flier miles is that you’re rewarded for your loyalty to an airline. One of the implicit promises made by airline reward programs is that you wouldn’t have to pay to cash in the miles. (The exception used to be expediting award redemption for tickets booked at the last minute.) But then airlines figured out that customers would pay for their award seats, and so the race was on to monetize award miles. The competition has become unusually heated recently. For example, if you want to upgrade to BusinessFirst on Continental Airlines, you may have to pay an “upgrade reward co-pay” of up to $500. United Airlines has a similar program. In response to negative feedback from frequent fliers, some of these fees have been ratcheted back down in recent months, but there’s no sign they are being reconsidered.

How to escape the fee: Some airlines still don’t charge controversial co-pays, including Southwest Airlines and JetBlue Airways. If you have miles in an airline that does, consider burning the points for something that doesn’t cost extra. And switching your loyalty.

A “convenience” fee to pay by credit card
Who charges it: Allegiant Air, RyanAir
How much: $14.99

Analysts believe the “convenience” fee for buying an airline ticket with a credit card has a bright future, and that it’s only a matter of time before being widely adopted. You can avoid paying it by buying the ticket in person at one of the airline’s ticket offices. Then again, it will probably cost you at least that much to make an extra trip to the airport. Perhaps the only reason more airlines don’t charge them yet is that they may be interpreted as a violation of existing credit card merchant agreements in the United States. Germany recently banned the Irish airline RyanAir from charging a credit card fee. Still, there’s immense pressure from the airline industry to add “convenience” fees to their tickets, and industry-watches say it’s just a matter of time before figure out a way to do it legally.

How to escape the fee: Avoiding Allegiant and RyanAir is easy, for now. But if more airlines adopt “convenience” fees, the only way out may be to buy your next ticket at the airport. Or to take the train.

Which of these new fees do you find the most egregious? We ran an online poll this morning (9/8) and here are the responses.

(Photo: l rargerich/Flickr Creative Commons)