As Rick Seaney, CEO of the fare-hunting site FareCompare.com, points out, "Airline fees are a fact of life." True enough. When shopping for an airfare, realize that nobody pays the advertised airfare. It's merely the base price before taxes and miscellaneous fees are heaped on.

Still, not all airline fees are created equal, and those differences can make a big difference to your bottom line. Seaney's handy domestic airline fee chart makes for extremely interesting comparison shopping. It is a rather grim confirmation of what we already knew: gouging has become depressingly commonplace in the airline business. Most airlines are now charging $15 for the first checked bag and $25 for the second. Reserving by phone can tack as much as $35 on to your ticket price. Having an oversized or overweight bag can mean getting whacked with hundreds of dollars extra. Want to change your non-refundable ticket? You're looking at a penalty of as much as $150. Though it's not listed on the chart, opting for a paper ticket instead of an e-ticket can also ratchet up your final tally.

Mr. Seaney's chart is a cheat sheet for air travel's heroes and villains. The white hat clearly belongs to Southwest, which not only offers the most free services (first and second checked bags, phone reservations, unaccompanied minors, curbside check-in, and non-refundable ticket change) but where it does impose a fee, the amount is often significantly lower than that of the competition. To a lesser extent, JetBlue, Virgin America, and ExpressJet also have consumer-friendly fee structures.

When faced with identical or nearly identical airfares on the same route, factor in fees and then choose wisely. If your family will be traveling with several pieces of checked luggage, for example, the difference in what you will actually spend can be big.