Ditching an expensive car or truck lease is a great way to cut costs and save money.

Until recently, your only option was to return the car to your leasing company -- if it would let you -- and pay a big penalty.

But now it's possible to transfer your lease to another owner using a Web site such as LeaseTrader.com or Swapalease.com.

Just sign up, create an ad that includes photos of your car and the terms of your lease, and wait for consumers looking for a car like yours to respond.

Posting a car on one of these sites usually costs $50 to $100. If someone agrees to buy your lease, there's an additional closing fee -- $95 for Swapalease.com and $250 for LeaseTrader.

Under the Swapalease system, the seller and buyer do most of the legwork in terms of getting the lease transferred. LeaseTrader.com facilitates the exchange of paperwork and other tasks, resulting in the higher fee.

The major finance companies initially were reluctant to allow lease trading. But most are now on board and taking advantage of the system by charging transfer fees that range from $75 to $595.

Fortunately, it's the buyer, not the seller, who usually has to pay that.

If a lease transfer sounds like something that could help you, here's what to do.

Start by checking the list of leasing company fees and policies posted on these pages at Swapalease.com and LeaseTrader.com.

You'll need the answers to these three questions:

• Will your leasing company permit a transfer?
• How much will it charge?
• Are there any special restrictions that might affect you? (Some leasing companies, for example, won't allow transfers within the last year of the contract.)
• Does the transfer include a contingent liability clause? (On Swapalease.com, look for the question that says: "Does Original Lessee Remain Liable?")

Danger! Danger!: Don't transfer your lease if it contains such a clause.

It means the lender will continue to hold you liable for the payments and the condition of the car if the new lessee defaults. You could even be on the hook for the purchase price if your buyer fails to turn the car in when the contract expires.

Some major leasing companies, including GMAC Financial Services, Toyota Financial Services, Wells Fargo Bank, US Bancorp and Mercedes-Benz Financial, don't impose contingent liability on their customers.

Others, including Chrysler Financial and Nissan Motor Acceptance Corp., make contingent liability a standard part of any transfer, at least as of early 2008.

But policies can change, so check with your leasing company before deciding against a lease transfer. You also can make a written request for that liability to be dropped, and sometimes the lender will agree to do so.

If it refuses, the only way to protect yourself is through an insurance policy such as Swapalease.com's "Lease Transfer Peace of Mind" plan. But there's a long list of potential charges those policies don't cover, they're very new, we don't know how well they work, and the premiums add to your cost.

So, in our opinion, contingent liability is a deal breaker. If you can't avoid it, don't do it.

If you're still good to go, the next step is checking out the leases being offered on comparable models.

If your payments are among the most expensive, you've used most of your miles or are especially eager to unload your lease, you may need to offer an incentive to attract a buyer.

You can give the buyer cash to offset a portion of the future payments or agree to pay the lender's fee or the cost of transporting the car to its new owner.

Now you're ready to total up all the costs and decide whether transferring your lease makes financial sense.

If it does, here's everything you'll need to post your car or truck on one of the lease trading sites:

• Contact information. Land line and cell phone numbers, e-mail address and home address.
• Vehicle information. The more specific the information you provide, the better chance you have of getting a buyer interested in your car. Include basic information such as year, make, model and style as well as the car's features and current mileage.
• Lease details. The date the lease expires, the monthly payment, the number of miles you're allowed to drive, the number of miles on the car, the name of the leasing company and the end-of-lease buyout price and excess mileage fee.
• Pictures. Take a number of shots from different angles of the inside and the outside of the car to hook potential buyers. Get the car washed and clean out the inside so you can showcase it at its best.

By Amy Buttell Crane

Interest.com Contributing Editor

Have a question about cars or your finances? Ask us at editors@interest.com.