New York (CNN/Money) - While a lot of Americans are putting their travel plans on hold, those who are still eager to hit the road are showing more interest in travel insurance.

"We've seen an increase in sales of 20 to 25 percent in the last month alone," said Peter Evans, executive vice president of Insuremytrip.com, an online marketplace with travel insurance from nearly a dozen companies, including Travel Guard and MultiNational Underwriters.

Travel during wartime Airlines slash flights Airlines relax booking rules Travel jitters?

Particularly popular right now are trip cancellation policies that cover almost everything that could go wrong with a trip. Most policies cover cancellations due to severe weather, your death or serious illness or that of immediate family (check each carrier's definition of "immediate family"). They also cover you if the tour operator, airline, or cruise company can't complete its obligations because of financial insolvency.

But -- and this is a big but -- the fine print abounds. Airlines that declared bankruptcy before you bought the policy are not covered by most policies. United is currently operating in bankruptcy, and American and other carriers are flirting with the same fate.

Some policies consider terrorism or State Department warnings valid reasons to cancel the trip -- others don't. Most cancellation policies will cover you if you are scheduled to travel from, to or through a city where there has been a terrorist event, according to Evans, though the same is never true for war or acts of war.

If you're just too scared to fly, you're probably out of luck. "The only company I know that will provide such a benefit is Travel Guard which pays a maximum of $250 under its 'change of mind' clause," said Evans.

For all that, you'll pay 4.5 to 7 percent of the price of the trip. For a $3,000 trip, you could shell out an extra $200 for insurance.

Such a policy may make sense for very involved journeys -- say an extended cruise, or a big package tour -- but aren't necessary if you're just flying somewhere, renting a car and staying in a hotel.

In the case of airlines, you won't always get your money back but you can reschedule your ticket. Airlines typically charge a fee of $50 to $100 to change your travel itinerary but are waiving this fee in light of the conflict with Iraq. (See "Airlines relax their booking policies.")

Hotels generally require that you simply cancel within 72 hours, and rental car companies are quite lenient when in comes to cancellations. Still, always take note of the cancellation policy before you make a reservation for anything.

Another breed of travel insurance gives you the option for extended medical coverage. If you plan to travel outside of the United States, find out whether your health insurance covers medical care abroad, and if so, to what extent. Many plans, including Medicare, do not cover health care outside the United States except, under limited conditions, in Canada and Mexico.

This extra medical insurance can cost anywhere from $50 to $1,000. Whether or not you need it depends on your health, the nature of your trip, and your destination. In a lot of countries medical care is inexpensive or covered by the national system.

Again, reading the fine print is critical. If you have a pre-existing condition, make sure it's not excluded. The same is true for adventure-related injuries. You'll want to also find out whether your bills are paid up front or if you'll be reimbursed after you foot the bill. (You should seek the former.) See if there is a deductible or daily limit and how long, if at all, you are covered after the initial illness or injury.

Some insurance companies sell all-inclusive travel policies that cover all of the above and then some. But these all-inclusive policies average about $200 and may cover a lot of losses that might already be under your health, life, car or home insurance, or protected by your credit card.

In fact, there are several minor categories of insurance that are probably not necessary or are covered elsewhere.

If you have auto insurance, you are typically covered for domestic and even international rentals. Many credit cards also cover car rental, and the car rental companies themselves sell insurance for the life of the rental if needed.

Should you lose your luggage, you're probably covered by your homeowners or renters insurance. If you travel with expensive computer equipment or jewelry, you may want take out a rider that will cover the full value of these goods. Also, most airlines will pay up to $2,500 for luggage they've lost.

Accidental death and flight insurance, which starts at $10 a flight, might seem like a good deal, but if you really want to provide for loved ones, you're best bet is to buy or beef up a regular life insurance policy. The average healthy person can buy life insurance for an annual premium that is not much more than these one-shot deals.