If You Don't Need It, Don't Take It

• For domestic and most international flights, there are very few liquids you can carry on the plane that cannot be purchased inexpensively at your destination. Bottled water, shampoo, lotion, bath gel, roll-on deodorant, toothpaste--all are personal items that can be bought almost anywhere on earth. In fact, some travelers may find that the speed with which they can pass through airport security offsets the inconvenience of buying a few personal toiletries once they arrive at their destination.
  
  Consider taking fewer items than you might normally pack. If you have toothpaste, do you really need to lug a bottle of mouthwash as well? You can pack mouthwash in your cheked luggage and carry a roll of breath mints on the plane.
  
  Also, consider switching to different types of products while travelling. A man can use a bar of shaving soap and lather up at his hotel just as easily as using a can of aerosol shaving foam. A bar of shaving soap is lighter, compact, takes up a fraction of the space as a can, and is not subjected to regulations restricting onboard liquids.
  
  You can also transfer a small quantity of aftershave, cologne or perfume to a smaller plastic container (3 ounces or less) to meet safety regulations, carry less weight and eliminate the risk of breaking or losing an expensive bottle of fragrance. Remember, just pack what you need for the duration of your stay.
  
  

The 3-1-1 rule

• All liquids brought aboard an aircraft in the United States must be in individual plastic bottles no larger than 3.4 ounces each. All bottled items must be inside one transparent, resealable plastic bag no larger than 1 quart in size. This is the Transportation Safety Administration's 3-1-1 rule. You can bring only one clear plastic bag of personal items containing liquids onboard an aircraft in carry-on luggage.
  
  

Checkpoint

• You can speed up your time by removing your plastic bag of liquids from a carry-on bag. Security regulations require that the plastic bags be screened separately from other items.
  
  There are exemptions for liquid medicines, but you must show a prescription or a doctor's signed statement of medical need to bring them aboard. Baby formula, bottled breast milk and nutritional liquids for people with special dietary requirements are also exempt from regulations. The Transportation Safety Administration says these items can be carried aboard an aircraft in "reasonable quantities," although the administration does not cite specific amounts. A good rule of thumb would be to carry on no more than you would be likely to use during the length of the roundtrip flight.