As if travel wasn't expensive enough these days, United Airlines has found a way to pass along more cost to customers. They will be charging some customers a new fee for checking more than one piece of baggage. 

People who buy nonrefundable domestic economy tickets, and who are not elite members of the airline's frequent flier program, will be charged $25 for a second checked bag beginning May 5 2008. The $25 fee for the second bag charged each time the luggage is checked. Customers were informed of the fee Monday on United Airlines website and on e-tickets sent to passengers.

So far no other carriers are matching the baggage fee. United estimates the new charges will give them more than $100 million in additional revenues. With the airlines industry pressured for profits, watchout for other airlines to follow suit in charging more for checking bags.

Check with your airline prior to flying to make sure they don't have new baggage charges.