Holiday travelers: Book now or you'll be sorry

The holidays are just around the corner, and you need to get cracking if you haven't yet booked a flight for a trip home or a vacation escape.

Thanksgiving, Christmas and New Year are the busiest travel periods of the year; and with the crowds come more competition for good fares and longer lines at the airport.

While fares are up slightly for the holidays this year compared to last, bargains can still be found, but you must act now, air-travel experts say.

Here are some tips to help you save money, time and hassle on holiday travel:

Check out fares online: There are legions of online travel sites for consumers who are looking for deals, including Travelocity.com, Orbitz.com, Kayak.com, Expedia.com, Lowestfare.com and Cheaptickets.com. Also go to the airlines' own Web sites, where cheaper fares may be found (and with no service charges). Be aware that some of the big travel sites, including Expedia and Orbitz, don't include flights on Southwest Airlines. (Southwest, which often has some of the lowest fares, doesn't supply information to online aggregators.)

Be flexible on travel days : You can save hundreds of dollars if you don't have to travel on the most popular holiday travel days.

"For Thanksgiving, varying the date of return makes the most difference," said John Rauser, of Seattle-based Farecast.com, a fare-predictor site that analyzes thousands of historic fare prices to predict what future prices will be.

Sign up for fare alerts . Various sites will send an e-mail message when the fare is lowered on a flight you register for. Some good ones are Yapta.com, Bestfares.com and Farecompare.com. Airfarewatchdog.com also tracks fares.

Not all of these sites track the same criteria or include the same airlines, though, so you may want to register for more than one when starting out.

Consider traveling on the holiday: If you are willing to gamble on availability, airlines often have cheaper seats on the actual days of the holidays.

Check on delays: Before you leave for the airport, check the status of your flight. Heavy holiday air traffic and weather problems can create delays that boomerang across the country. Phone your airline for information on flight delays, or check Sea-Tac Airport's real-time flight status at http://hosting.portseattle.org/fids/.

Cut down on airport stress: You can print out your boarding pass from airline Web sites up to 24 hours before a flight, then go directly to the security line if you check your bags with a skycap (or travel with carry-on only). That lets you avoid the waits at airline check-in counters.

Know the carry-on rules

To find what's allowed (and what's forbidden) in carry-on luggage, see the Transportation Security Administration Web site, www.tsa.gov.

The TSA's basic guidance for carry-on liquids is "3-1-1," that means you can carry three ounces of any liquid or gel in a one quart plastic bag, but only one bag allowed per traveler.

If all else fails, drive :

According to the Bureau of Transportation Statistics, most people, about 91 percent, do their long-distance holiday travel in their own vehicles. Just like with flying, though, you can save yourself time and money by traveling at off-peak times. The day before Thanksgiving is the most heavily traveled day of the year on the roads.

Kristin Jackson of The Seattle Times travel staff contributed to this report.