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Charges for checked bags

If you plan to check your luggage at the airport, you should know that many airlines now charge for this service. American Airlines, United Airlines, and US Airways charge $15 for your first checked bag, $25 for a second, and $100 to $200 for each additional piece. Spirit Airlines seeks $25 each for your first and second piece of checked luggage, plus $100 each for your third, fourth, and fifth. Air Canada, Delta Air Lines, Continental Airlines, Frontier Airlines, and Northwest Airlines continue to allow each passenger to check one bag for free, but now request $25 for a second bag.

Keep in mind that these increasing luggage fees are assessed one way only, so you should double the expense if you plan to fly round trip. What's more, higher fees may apply depending on the weight and dimensions of your checked items. For example, American Airlines and US Airways both charge $50 for your first checked bag if it weighs more than 50 pounds and $100 if it weighs more than 70 pounds.

Most airlines allow each passenger one carry-on bag and a personal item, such as a purse, laptop, or briefcase. Typically, carry-on bags must not exceed 45 linear inches or 40 pounds. Bags that are too large or too heavy to fit in an overhead bin or beneath a seat may need to be checked. However, if you're in the military reserves and/or a member of a frequent flyer reward program, you may be exempt from all luggage fees.

Seating fees and more

Another method airlines have started to use to combat the cost of fuel is charging additional fees for requesting aisle and window seats or seating away from bulkheads and restrooms. At the time passengers make their reservations, Spirit Airlines charges $15 for an exit row seat, $10 for an aisle or window seat, and $5 for a middle seat request. AirTran Airways asks for $6 for advance, guaranteed seat assignments.

In addition to charging $10 during online check-in for guaranteed aisle or window seating, US Airways is now asking passengers to pay for their soft drinks, requesting $2 for soda, juice, and bottled water, and increasing the cost of alcoholic beverages from $5 to $7. Air Canada is raising additional revenue by charging $2 for a "comfort pack," which includes a pillow and blanket—items previously provided gratis.

Telephone vs. online booking

The method by which you arrange your flight can also impact your savings. For example, JetBlue charges an extra $15 per ticket for passengers who book by phone rather than through its website. AirTran Airways charges $10, Northwest Airlines charges $20, and Air Canada charges $25 per reservation made over the telephone. US Airways has raised the cost of using its call center to book flights to $25 for domestic flights and $35 for international travel. At its city or airport ticketing offices, passengers now pay $35 to book domestic travel and $45 for international flights. Many airlines also offer Internet deals, which are available exclusively to online customers.