For years, Caroline Lamarre dreaded the annual "Secret Santa" tradition of picking a name out of a hat and giving her secret match a gift.

She'd have to find a time when all her friends could get together to draw names, and people would have to draw again whenever they picked themselves or a sibling.

So it only made sense for her to let a computer do all that.

Several Web sites have emerged to help people like Lamarre coordinate the popular holiday game.

"This year it probably took me about five minutes," said Lamarre, 23, who used Elfster.com for the second time. "My friends think I'm a nerd, but they like it."

These free sites typically work by letting users enter the e-mail addresses of their Secret Santa participants. Computers make matches and notify participants. Some even let you say in advance who can't be matched with whom and make sure no one is assigned the same gift-giver two years in a row.

Participants also can create "wish lists" and "do not need" lists, and secret givers can pose anonymous questions like T-shirt size or favorite color.

Peter Imburg, the creator and "main elf" of Elfster.com, said usage has nearly tripled this year to more than 70,000 people. Last year, when the service launched, about 24,000 people participated in 3,000 exchange groups.

"I never exactly envisioned myself as being Santa's little helper, but I feel that the role suits me, and I rather enjoy it," Imburg said.

Like several site creators, Imburg said he started his site to make his family exchange easier. Now, the Oakland, Calif., computer programmer says he spends hours creating new site features, including one that calculates users' "Naughtiness Factor" and "HoHoHo Rank" ratings based on their participation in the site.

Two New York City software engineers, Franco and Paolo Yuvienco, built GuessList.com to coordinate their 20-person family exchange last year. Word spread and 3,300 people used it. This year they bought the domain names SecretSanta.com and SecretSanta.net and began publicizing the site, drawing 23,000 participants.

Each site has its own twist on the classic gift-giving game.

In some cases, people have to accept an invite to participate before the computer makes the matches. Some sites partner with Amazon.com and get commissions for gifts purchased there.

At TopSecretSanta.com, a site based in Canada, the theme is undercover agent. Santa is shown wearing an earpiece, and participants are given a "mission" to get someone else a gift.

People who use SecretSanta.com can choose their own party theme screens and set up exchanges for Hanukkah and Kwanzaa. The developers are looking to make the site available in other languages, too.

Users say shifting to the Web was simple and made gift-giving easier.

"Most of us liked that you can put up a wish list," said Jazmine Valencia of Boca Raton, who had her 12-person Elfster.com exchange Saturday.

DrawNames.com creator Janie Schaeffer of Raleigh, N.C., said people frequently return to check wish lists for birthdays and other occasions.

Some have even adapted it to assign summer camp bunks or choose where to eat. One person, she said, even used it to help him choose the draft order pick for his fantasy football league.