As millions of Americans plan their summer vacations, the prospect of identity theft (search) is more prominent than ever.

"This is big business, this is not a cottage industry anymore," said Linda Foley, executive director of the Identity Theft Resource Center.

"There are organized identity theft crime rings throughout the world who target American tourists and they're looking for people who are distracted, busy families who aren't paying attention to their surroundings and the people around them," Foley said. "Doesn't that sound like the typical tourist?"

In 2001, the Federal Trade Commission (search) submitted more than 220,000 complaints from identity theft victims to its database. Last year, those complaints increased to 380,000, and American consumers reported losing more than $343 million in 2002 to the crime.

"I think people are really becoming aware that it is probably the fastest growing consumer problem in the United States," said Jim Vaules, a fraud consultant with Lexis Nexis, which provides identity verification products for corporations and governments.

So when Americans drive, fly, sail or take the train to their summer destinations, they should take several precautions to safeguard their identities.

First and foremost, do not carry a Social Security card, Vaules said.

"People carry their Social Security number written on a piece of paper and also the Social Security number of their husband or their children. Someone gets access to that and of course, they not only have one, but three or four numbers," Vaules said.

Foley noted that her organization's victim guide, which details what to do if your wallet or Palm Pilot is stolen, is the most popular ID theft guide on that site and illustrates the need to safeguard personal items.

"Don't carry anything with you that you're not willing to lose," she said.

Foley added that Palm Pilots (search) and laptops left in hotel rooms should be password protected, and wallets should be in sight at all times.

"If a wallet is not where you have complete control of it at all times, you are a potential target," she said.

Renee Beauregard, executive director of the Colorado-based Consumers United Association, pointed out the items people normally carry around can reveal more than they realize.

"When you think about what's in your wallet or what you might have on your computer, it's kind of mind-boggling," she said.

Lexis Nexis provides a list of recommendations for travelers:

- Watch out for "shoulder surfers" at ATM machines who may try to steal PIN numbers. Always shield the ATM keypad with your hand as you enter your PIN.

- Don't carry personal financial information in your wallet or checked luggage.

- Limit the number of credit cards you carry.

- Leave personal checkbooks at home. Use traveler's checks instead and separate receipts from the checks.

- Have mail held at the post office while away on vacation. Identity thieves could use bills and "pre-approved" credit card offers to steal personal information.

- Stay at hotels with in-room or front desk safes. Keep your hotel room locked and don't leave credit-card receipts in the room.

- Avoid making credit card calls on public phones. Use pre-paid calling cards instead.

- Vigilantly monitor your credit history and check your credit report every couple of months after any extended travel, particularly to a foreign country.

- Be prepared for anything: Keep a list of all account numbers, credit limits and expiration dates, as well as customer service phone numbers and addresses in a safe place so you can immediately report a problem should one arise.

Many banks, credit unions and other financial institutions offer their own tips for keeping people safe from ID thieves.

SunTrust, for example, advises that travelers keep a photocopy of their passports. If a passport is stolen, go to the closest U.S. embassy or consulate.

Consumers Union encourages people to keep their driver's license numbers off personal checks, and urges them to shred mail containing their Social Security number, credit-card account numbers or other personal information.

If you are a victim of identity theft, the FTC recommends having a fraud alert placed in your file, closing accounts that thieves have accessed and disputing unauthorized charges.

Above all, Beauregard said the best defense against identity theft is awareness.

"There's a lot more that needs to be done in terms of awareness because the criminals are always one step ahead in trying to get this information from people and it's hard to prevent," Beauregard said.