Buffett, the famously frugal billionaire, has donated his 2001 Lincoln Town Car for an eBay auction starting Sept. 12 to raise money for Girls Inc., a youth organization his family has long championed. He is even throwing in his vanity license plate: THRIFTY.

"I don't want to sound like a used-car salesman, but this car is a real cream puff," Buffett said in a telephone interview from his office in Omaha. "You just have to get behind the wheel of this vehicle."

Charities have long sold items owned by celebrities, but eBay and the Internet have pumped new life into this fund-raising technique, increasing returns exponentially.

Last year, a Harley-Davidson motorcycle autographed by guests on "The Tonight Show with Jay Leno" raised $760,095 for the American Red Cross to help it serve victims of the Asian tsunami, setting a record on eBay. In 2002, Tiger Woods auctioned off a round of golf with himself for four people and raised $425,000 for his foundation, which supports programs that serve underprivileged children.

The United Way of America used its own Web site to auction off the gift bag George Clooney received this year for his services as a presenter at the Academy Awards. The gift bag raised $45,100, which was $27,100 more than the value of the items in it.

"The Internet increases your reach, drawing people from around the country and even internationally," said Sheila Consaul, a United Way spokeswoman.

(Nonetheless, Consaul said the United Way would think twice before accepting another gift bag because only 27 of the 68 items in it could be transferred to someone other than Clooney, who sits on the United Way's board. "It was a little more challenging to pull off than it sounded," she said.)

Since 2000, more than $81 million has been raised for charity on eBay from regular vendors committing a part of their sales to nonprofit groups and by charities selling items directly. On any given day, more than 8,000 such sales are going on.

Conventional sellers are charged standard fees that, under a policy effective Oct. 1, will be returned to them in direct proportion to the percentage of the final sales value they have pledged to donate. For example, if conventional sellers send 30 percent of their revenues to charity, eBay will return 30 percent of their fee. Nonprofits selling items on eBay via the Giving Works program pay no basic fees.

"Interest from nonprofits has been amazing," said Kristin Cunningham, senior manager of Giving Works. "Among people who are always having to ask for a check, anything that puts a new spin on fund raising can be exciting."

Buffett has experience with that phenomenon. In 2000, he began donating a lunch with himself to the Glide Foundation, a charity providing help to the poor that is affiliated with the Glide Memorial United Methodist Church in San Francisco and was supported by Buffett's late wife, Susan Thompson Buffett.

For the first three years, the lunch was auctioned off at Glide's annual benefit, raising an average of about $27,000 each time, Buffett recalled. "Then they put it on eBay four years ago," he said, "and the first year there, it went for $250,100, and I like those kinds of returns."

This year, the lunch raised $620,100 for Glide, which has a budget of about $12 million. "That's substantial for us," said the Rev. Cecil Williams, the chief executive of Glide's national and international ministries.

Buffett, who recently donated the bulk of his fortune to the Bill and Melinda Gates Foundation and other charities, said it had been his daughter's idea to offer the Lincoln to Girls Inc. He said he had bought a Cadillac as a show of support for Rick Wagoner, the chief executive of General Motors, "and she asked me what I wanted to do with this car."

"I told her she could do what she wanted with it," he added, "and this is what she came up with."

The Buffett family has a long history with Girls Inc. of Omaha, the local affiliate, said Roberta Wilhelm, the organization's executive director. In 1975, Buffett helped it find its first home, in a church basement in Omaha, and the Buffetts' daughter, Susie, sits on the boards of the local and national organizations.

"It's terrific," Buffett said of the charity. "The girls, they come there after school and get help with homework, hot meals, access to computers, getting support and experiences they would not have otherwise. It evens the playing field a bit."

Girls Inc. of Omaha was one of four youth organizations in the city to benefit from an annual golf tournament Buffett sponsored. And in 1999, he planted a stock tip inside his wallet and gave it to the charity to sell at auction.

The wallet sold for $210,000, but it raised much more for the charity. "The buyer said he would share the tip in it with others who gave money to us," Wilhelm said, "and that generated a lot of other gifts." She added that the tip paid off for the buyer, John Morgan. Morgan, an Omaha native who lives in Minnesota, became a big supporter of Girls Inc. and once served on its national board.

"We got a lot of mileage out of that wallet," Wilhelm said.

Buffett said he had never used the wallet much. "Kind of like my car," he said. "I only put about 14,000 miles on it in four years, going to the office, which is about a mile from my house, and to the airport, which is about three miles away.".