With more than 100,000 travel agents working in the United States, the challenge isn't finding one, but choosing the right one. Here are tips for doing that:

* Ask friends and colleagues for a referral, just as you would when looking for a dentist or contractor.

* Check affiliations. Membership in organizations such as the American Society of Travel Agents (ASTA) and the Cruise Line International Association (CLIA) indicates that the agent has agreed to a code of ethics. (They can be excommunicated from the group for failing to adhere to them.) You also can dig one level deeper and ask for the industry affiliations of a tour operator they've recommended. The U.S. Tour Operators Association, for example, not only vets its members but requires them to put money into an escrow account in case they go out of business. To find ASTA members, visit www.travelsense.org. The site allows you to search for agents by location, specialty, your destination, or all three at once.

* Check credentials. The Travel Institute, a nonprofit training center in Massachusetts, offers certification. A CTA, or Certified Travel Associate, has completed at least 12 travel-related courses, has worked in the industry for at least 18 months and has passed a test. A CTC, or Certified Traveler Counselor, has completed at least 24 courses, has at least five years experience and has passed a test. The institute also trains destination specialists. Certified agents, and those further certified as specialists, are listed at www.thetravelinstitute.com, with links to each agent's site.

* Ask for references. A good agent should have satisfied customers willing to share their experience, says Alexis Benson of the Travel Institute.

* Ask questions. Ask where they've been, where their colleagues in the office have been, and where they've sent large numbers of people. "If no one in the office has been anywhere but Cancun and you're not going to Cancun, maybe they're not the ones you want," says Heather Dolstra of Democracy Travel in D.C.

* Listen for questions. Agents should feel you out before suggesting a destination or particular cruise line. "If you tell me you want to go to Mexico, I shouldn't say, 'Great, I can set you up in Puerto Vallarta,' " says Kathy Sudeikis, president-elect of ASTA. "Agents should be asking what trips you've taken in the past that you've enjoyed, whether you prefer quaint, rustic or luxurious, or if you had to choose between a Hyatt and a Motel 6, which would it be. They should ask you what you like to do: If you like sightseeing, you have to go to certain places in Mexico."

* Decide if you need a specialist. Increasingly, agents are marketing themselves as specialists in either certain types of travel or certain destinations. Many agents interviewed said they can research an unfamiliar destination, but admit that it will take them more time than planning a trip to a place they know well. All acknowledge that familiarity breeds expertise, but on the other hand, as Dolstra put it, "Are you looking for someone you can have a relationship with in planning lots of trips, or a one-shot Johnny?"

-- Cindy Loose