With gas prices at record-highs, you may be thinking about alternative travel methods, like flying. Unfortunately, airline carriers also rely on fuel.

Tuesday, oil prices were nearing $120 a barrel. To make up for their extra costs, several companies have added baggage fees to passengers carrying on more than one piece of luggage.

Five major airlines have added a $25 fee to passengers who check more than one bag. Many of the fees will go into effect on may 5th. Airline companies say it's just one way to help pay for the rising cost of fuel.

Travelers who tend to pack a little heavy, may soon want to change their habits. If you're flying on a major airline, you're only going to be allowed one check-on bag...any extras, and you'll be charged.

"They already charge so much to fly now and now they're going to charge extra for the bags. That's awful," said Derenda Day of Phoenix.

Airline carriers say there are some exceptions. The fees apply mostly to domestic flights for passengers who don't belong to a frequent flier program.

They claim the outrageous fuel prices gave them no other choice. A representative from United Airlines says fuel is their highest expense of all. The company estimates it will spend two-billion more dollars on fuel this year than last.

"I don't think they're going to lower our tickets. I think that's going to go up as well. Then we'll have this 25 dollar fee and they're going to blame both on gas. You can't have your cake and eat it too," said Alka Sharma of West Palm Beach, Florida.

The Baggetts, of Reno, rarely use air travel, but say that's because ticket prices are expensive for a family of seven. Now, with additional fees and the high cost of gas...it's leaving travelers like them with few choices.

"Well, we bought an economy car, but we can't fit everyone in it, so you just go less places and do more at home," said mother of 7, Kenya Baggett.

Some complain that the extra fees will only cause further crowding problems on planes.

"I pack two bags a lot of times. I am just going to take more stuff onto the plane and I don't know what they're going to do about that. They'll have new rules after this. It's going to be, 'you can only have a handbag, or you can only have this and that," said Sharma.

While customers try to adjust to the new fees, many of them wonder, what will be next? With the cost of fuel going up, not down, many aren't sure just how many more fees they can take.

"We can just go with it and hope for better times. What can we do?" said Sergui Dotsento of Chicago.

So if you think flying is expensive now, just wait. Some airlines say there may be more fees to come. American Airlines representatives say they aren't charging any baggage fees right now, but they are watching the market and say they will have to adjust to the costs if fuel prices continue to rise.