From the Boston Globe, by Richard P. Carpenter, Globe Staff, 11/26/00

1.  If you wear a fanny pack, keep it under your clothing.  Thieves can quickly cut away those
wrap-around pouches while you are on an escalator or moving walkway.

2.  To foil dishonest employees who may help themselves while loading your suitcases, pack valuables in the middle of your luggage and never in the zippered outer compartments, and use sturdy locks.  (On the trip home, I usually pack dirty laundry in the outer compartments; crooks are welcome to it).

3.  If you set off an alarm at the security checkpoint, ask to be given your bags from the X-ray conveyor belt before the routine body check begins.  Otherwise, unscrupulous types may walk away with your baggage while you are being searched.

4.  Use a brightly colored bag or special backpack for your laptop.  While people are talking on pay phones, thieves have been known to replace cases left on the floor with similar cases.  Trick is, make it difficult for the thief to exchange your luggage.