Because of the Christmas Day attempted plane-bombing, the Transportation Security Administration has put in place additional security measures. Procedures will vary from airport to airport and be implemented as need is determined.

Domestic security will include explosive detection canine teams, law enforcement officers, gate screening, electronic detection machines, behavior evaluation and other behind-the-scenes measures.

Passengers on international flights to the U.S, should expect increased gate screening, including pat-downs and bag searches, plus use of body imaging and explosives trace-detection machines.

Passengers flying from or through countries named as promoting state-sponsored terrorism — Iran, Cuba, Sudan and Syria — plus those from or transiting through Pakistan, Nigeria and Yemen will be subject to heightened security procedures.

During flight, passengers may be asked to stow personal items, turn off electronic equipment and remain seated.

TSA has issued an advisory for passengers "to help make their passage through the airport as efficient and comfortable as possible." Check the TSA Web site for updates prior to departure, and allow for extra pre-board time at the airport in case of longer-than-usual security lines.

PACK SMART

• Pack an organized carry-on bag using layers — clothes, then electronics, more clothes, and then any heavier items. This will help transportation security officers see what's in your bag. Some items, simply by the way they are packed, can appear to be potential threats in an X-ray image.

• Do not pack oversized electronics (laptops, full-size video game consoles, DVD players and video cameras that use cassettes) in your checked baggage if feasible. You will be required to remove these items from your carry-on bag and submit them separately for X-ray screening. Small electronics, such as iPods, may remain in your carry-on.

• Prepare your one-quart-sized, clear plastic, zip-top bag of liquids (three ounces or less for individual containers) before arriving at the airport.

• Pack coats and jackets in your checked baggage when possible, as they must go through the X-ray machine for inspection if being worn.

• Do not wrap gifts, as a security officer may need to unwrap your packages to inspect them.

• Undeveloped film should go in your carry-on bag. You can declare film that is faster than 800-speed to a TSA officer for physical inspection in order to avoid potentially damaging X-rays.

• If you're in doubt about whether you can bring an item through the checkpoint, place it in your checked bag or leave it at home.

DRESS THE PART

Transportation security officers must identify any metal detected at the checkpoint. If the metal detector sets off an alarm when you pass through, you will be required to undergo additional screening that includes a hand-wand and pat-down inspection.

Items that might set off an alarm on the metal detector include:

• Keys, loose change, mobile phones, pagers, and personal data assistants (PDAs).

• Heavy jewelry (including pins, necklaces, bracelets, rings, watches, earrings, body piercings, cuff links, lanyards or bolo ties).

• Clothing with metal buttons, snaps or studs.

• Metal hairpins, barrettes or other decorations for the hair.

• Belt buckles.

• Underwire bras.

WHAT ELSE?

Body piercings — Certain metal body piercings may set off the metal detector, which will result in additional screening. If this is required, you may ask to remove your body piercings in private as an alternative to the pat-down search.

Head coverings — You are permitted to wear head coverings and religious garments during the screening process. You may be directed to additional screening if your headwear or clothing (religious or otherwise) is loose-fitting or large enough to hide prohibited items.

Shoes — Travelers are required to remove their shoes before entering the walk-through metal detector at all U.S. airports and put them through the X-ray machine for inspection.

BE DOCUMENT-READY

The items you'll need to present to a TSA officer at checkpoints are:

• Boarding pass

• Government-issued identification such as a valid passport or driver's license. If your ID (not required of children 17 and under) is missing, you'll be required to provide information to help verify your identity and will be subject to additional screening.

Irene Croft Jr. of Kailua, Kona, is a travel writer and 45-year veteran globetrotter. Her column is published in this section every other week.