Tip: Check airline carry-on charges at two websites

Before you head to the airport, you might want to check whether that carry-on bag gets a free ride.

With more airlines charging a range of fees on everything from first-checked bag to oversized luggage, it's hard to know how much extra you will pay until you get to the airport. SkyCap News (skycapnews.com) collects and publishes fee information from several of the biggest domestic airlines. For example, if Fido is flying with you, he will cost you an additional $75 on Southwest Airlines, but he could fetch as much as $250 for United Airlines. Similarly, the website Smarter Travel offers a downloadable airline fees guide at smartertravel.com. The link to the guide is toward the bottom of the home page.

Both sites also feature tips and advice from seasoned travelers.