The Dallas Morning News gives us the run down of the different charges Airlines make these due to their increasing costs:
Airlines are adding fees and charges aggressively as they grapple with rising fuel costs.
AMERICAN AIRLINES
$5 to redeem a frequent-flier award online, up from $0
$6 for a sandwich or liquor,
up from $5
$15 to check the first bag (each way), up from $0
DELTA AIR LINES
$25 for booking a trip over the phone, up from $20
$100 for an unaccompanied minor on nonstop flights, up from $50
$100 for transporting a pet in the cabin, up from $75
UNITED AIRLINES
$25 to check a second bag (each way), up from $0
$150 to change a nonrefundable ticket, up from $100
OTHER AIRLINES
US Airways: $5 and up for a window or aisle seat in the first rows of coach, up from $0
Northwest: $50 for each bag weighing over 50 pounds, up from $25
Frontier: $100 to transport antlers, up from $75
SOURCES: The airlines; Dallas Morning News research