Be prepared for extra airline charges

$25 each way for a second checked bag: United, Delta, Northwest and US Airways

$15 each way for first checked bag: American Airlines

$50 each way for a checked bag weighing more than 50 lbs: most U.S. domestic airlines

$150 (up from $100) to change a ticket: United

$25 (up from $20) to book your flight over the telephone: Delta

$25 'handling charge' to book an award ticket, via the telephone, that has a leg on another airline: Delta

$5 to $30 for a Choice Seats option (aisle or window in the front of the plane) if you check in online 24 hrs before departure: US Airways

$25-$35 for service, by phone, from a special customer service agent for 'travel and accomodation solutions' when your flight is delayed: Air Canada

In the volitale airline industry, things can change on a daily basis. Be sure to check with the airline you'll be flying to confirm current charges. Also, many airlines have excluded from extra fees their elite members and/or passengers traveling on full fare Business or First Class tickets.