(MONEY Magazine) – As you do some damage with your credit cards this holiday shopping season, keep in mind that there's an easy way to do some good at the same time. Shop online at one of the growing number of giving websites that link you to popular Net stores--including Amazon.com, 1-800-Flowers and Dell--and a portion of what you spend will go to charity. You pay the same prices that you would at the retail sites, and you can generally pick a beneficiary from a list of charities.

While at least eight such sites are vying for your good intentions, the ones we like best are those that funnel the most money to charity and are up front about how much that is. (Typically, an online retailer agrees to pay a fee to the donation site, usually a commission for each customer or purchase. A portion of those fees goes to the charities themselves.)

Our favorite site is www.4charity.com, which links you to many of the most popular Web retailers, lets you choose from about 30 charities (including the American Red Cross and Amnesty International) and, unlike most other sites, passes along 100% of the merchant fees. What's more, the portion of your spending that goes to charity is substantial: 12.5% on eToys purchases (plus $5 for each new customer) and 20% at both the Sharper Image and Cooking.com.

One caveat: 4charity.com cycles merchants in and out of its program, so at any given time you may not be able to shop with a particular retailer. If you can't find the store you want, try www.charitymall.com, which also donates 100% of merchant fees, or www.charitableway.com, a new site that passes along at least 90%. Another site, www.igive.com, passes along only 50% but has the largest lineup of merchants and charities we found and is the only one that enables you to take a tax deduction for your donation by making it voluntary--you can choose, in other words, to get a cash rebate instead of supporting a charity.

--JUDY FELDMAN