The Giving Pledge
About 40 billionaires have signed on to "The Giving Pledge," a charitable initiative started by Warren Buffett and Bill and Melinda Gates. Each has made a commitment to give the majority of their wealth to the causes and charities of their choice.
Forbes estimates there are 403 billionaires in the U.S. Some, including a talk show host, haven't commented publicly on the pledge, and others, including a California gubernatorial candidate, reportedly have declined.
You don't have to be a billionaire - or even have money -- to help others. Here's how you can find volunteer opportunities in your area.
Warren Buffett
Net worth: $47 billion, Forbes estimates.
What is one of his nicknames?
Here's how he made his fortune.
Why did he start The Giving Pledge with Bill and Melinda Gates?
Bill and Melinda Gates
Net worth: $53 billion
Here's how Bill made his fortune.
How did Bill Gates and Melinda Ann French first meet?
The couple said they started The Giving Pledge for a specific reason.
Michael R. Bloomberg
Net worth: $18 billion
Here's how he started making his fortune.
He makes astonishingly little as mayor of New York City.
Why did he sign The Giving Pledge?
Is he married?
Barry Diller and Diane Von Furstenberg
Net worth: $1.2 billion
He began making his fortune in this medium. What is his wife famous for?
Here's what Von Furstenberg said about their marriage.
The couple pledged, but they don't say why.
Larry Ellison
Net worth: $28 billion
For what is he well known?
He started out making money in this line of work.
He took a pay cut; what's his current salary?
Why did he sign The Giving Pledge?
Barron Hilton
He took a menial job when he joined the family business.
Hilton also owned this football team.
Why did he sign The Giving Pledge?
What is his relationship to famous socialites Nicky and Paris Hilton?
George Lucas
This movie breakthrough helped give him the clout for his "Star Wars" (see clips) success.
Why did he sign The Giving Pledge?
How much did "Indiana Jones and the Kingdom of the Crystal Skull" (see clips) gross worldwide?
Thomas S. Monaghan
Net worth: The Domino's Pizza founder sold his stake for $1 billion.
Here's how he got his start.
What is he doing with his fortune?
Why did he sign The Giving Pledge?
He realized a boyhood dream by purchasing this baseball team.
In 1995, Pierre launched this online auction site.
This happened as soon as it went public.
Why did they sign The Giving Pledge?
What foundation did they found?
Net worth: $11 billionHere's how he got his start.
What is he doing with his fortune?
Why did he sign The Giving Pledge?
He realized a boyhood dream by purchasing this baseball team.
Pierre and Pam Omidyar
Net worth: $5.2 billion
In 1995, Pierre launched this online auction site.
This happened as soon as it went public.
Why did they sign The Giving Pledge?
What foundation did they found?
Ronald O. Perelman
Here's how he got his start.
Why did he sign The Giving Pledge?
How many times has he been married?
T. Boone Pickens
Net worth: $1.1 billion
He got his start creating this company.
He holds extensive rights to this important commodity.
Why did he sign The Giving Pledge?
What is his memoir called?
David Rockefeller
Net worth: $2.2 billion
Rockefeller was given a helping hand to start out.
His parents helped found a famous museum.
Why did he sign The Giving Pledge?
Ted Turner
Net worth: $1.8 billion
Turner made his fortune starting this 24-hour news channel.
He lost a chunk of his billions in two years.
Why did he sign The Giving Pledge?
He still owns more of this than anyone in the U.S.
Sanford and Joan Weill
Net worth: $1.8 billion in 2008, but dropped from Forbes' list a year later.
How did Sanford get his start?
He rose to lead a major financial concern, only to watch it crumble.
Why did Sanford and Joan sign The Giving Pledge?