World's Youngest Millionaires of 2008

We've seen this year's Forbes Magazine's list of the world's richest people but we've never been introduced yet to the world's richest AND youngest people.

And so we bring you the list of the World's Youngest Billionaires 2008.

Heading the pack is a 23-year-old, self-made billionaire who made money from the website he created: Facebook.com. With estimated net worth of $1.5 billion, Mark Zuckerberg is considered the world's youngest billionaire.

Below is a list of the richest and youngest people in the world - all of them billionaires - ranked based on age.

#1. Mark Zuckerberg

Age: 23

Fortune: self made

Source: Facebook

Net Worth: $1.5 bil

Country of Citizenship: United States

Industry: Technology

Marital Status: single,

Mark Zuckerberg founded addictive social networking site Facebook in February 2004 from his Harvard dorm room. Left school for Silicon Valley later that year; scored initial $500,000 investment from PayPal cofounder Peter Thiel. Venture firms soon swooned, among them Accel Partners and Greylock Partners. Today Facebook boasts 66 million active users. Estimated annual sales: $150 million. Microsoft bought 1.6% stake for $240 million last October; deal led many to suggest the company is worth $15 billion.

#2. Hind Hariri

Age: 24

Fortune: inherited

Source: inheritance

Net Worth: $1.1 bil

Country of Citizenship: Lebanon

Industry: Diversified

Marital Status: single

Youngest child of slain Lebanese Prime Minister Rafik Hariri. she inherited stake in family's construction, banking and media holdings. Graduated in 2006 from the Lebanese American University in Beirut. Sticks close by mother Nazek in Paris, where she attracted attention during recent fashion shows. At 24, one of the world's youngest billionaires.

#3. Albert von Thurn und Taxis

Age: 24

Fortune: inherited

Source: diversified

Net Worth: $2.3 bil

Country of Citizenship: Germany

Industry: Diversified

Marital Status: single

The youngest billionaire in the world for years, Prince Albert von Thurn und Taxis now slips to third place. He appeared briefly in Forbes ranks at age 8 but officially inherited fortune on his 18th birthday in June 2001. Went to high school in Rome; studied economics and theology in Scotland. Lives in a family castle, Schloss Emmeram, with his mother, Gloria, and older sisters Maria Theresia and Elisabeth. Racecar driver, tours with a German auto-racing league.

#4. Yang Huiyan

Age: 26

Fortune: inherited

Source: real estate

Net Worth: $7.4 bil

Country Of Citizenship: China

Industry: Real Estate

Marital Status: married,

Yang Huiyan received 58% stake in real estate developer Country Garden from its main founder, her father, Yeung Kwok Keung. She's now China's richest woman. Not much else known about her other than the fact she is an Ohio State grad and her wedding video is posted on YouTube.

#5. Fahd Hariri

Age: 27

Fortune: inherited

Source: inheritance

Net Worth: $2.3 bil

Country of Citizenship: Lebanon

Industry: Diversified

Marital Status: single,

Youngest brother of Saad Hariri, the Lebanese parliamentary majority leader; older brothers Bahaa and Aymin and mother, Nazek, are all also billionaires. Owns a stake in family businesses including construction, banking and media holdings. He serves on board of Beirut's Future Television Network, a terrestrial and satellite TV network.

#6. Aymin Hariri

Age: 29

Fortune: inherited

Source: innheritance

Net Worth: $2.3 bil

Country of Citizenship: Saudi Arabia

Industry: Technology

Marital Status: married, 1 child

Son of slain Lebanese prime minister Rafik Hariri, who left behind a $16.7 billion estate in 2006. Now based in Riyadh, helps watch over family construction and investment company Saudi Oger for older brother Saad Hariri, the Lebanese parliamentary majority leader. Plus has hands in U.S. government contracting: cofounded and chairs identity management software firm Epok, based outside Washington, D.C., which sells to federal and state customers.

#7. Begumhan Dogan Faralyali

Age: 31

Fortune: inherited

Source: media

Net Worth: $1.0 bil

Country of Citizenship: Turkey

Industry: Media/Entertainment

Marital Status: married

A daughter of billionaires Aydin and Isil Dogan. Began career as Arthur Andersen consultant in New York and later advised Europe's leading media and technology firms. Rejoined family media business in Turkey by establishing corporate communications department of Dogan Holding and became its president.

#8. Xiaofeng Peng

Age: 33

Fortune: self made

Source: solar energy

Net Worth: $2.5 bil

Country of Citizenship: China

Industry: Energy

Marital Status: married,

Started out with a trading company that grew into a large exporter of Chinese-made solar panels. Now nicknamed Light, this solar energy newcomer took his solar energy company, LDK Solar, onto Nasdaq in 2007.

#9. Malvinder & Shivinder Singh

Age: 35/32

Fortune: inherited

Source: pharmaceuticals

Net Worth: $2.5 bil

Country of Citizenship: India

Industry: Pharmaceuticals

Marital Status: married, 3 children

Both Duke University grads, the Singh brothers control generic drug maker Ranbaxy Laboratories, founded by their grandfather. Malvinder is chief executive of Ranbaxy, and Shivinder also runs Indian hospital chain Fortis Healthcare, which went public in 2007. Brothers also recently listed financial services arm, Religare Enterprises.

#10. John Arnold

Age: 34

Fortune: self made

Source: hedge funds

Net Worth: $1.15 bil

Country of Citizenship: United States

Industry: Investments

Marital Status: married

Raised by a lawyer dad and accountant mom, Arnold whizzed through Vanderbilt University in three years. He became an oil trader for Enron, supposedly earning $750 million for the company in 2001, when he was just 27. He went into business for himself after Enron collapsed a year later. Today he runs hedge fund Centaurus Energy.