Facebook CEO Mark Zuckerberg was one of 17 billionaires this week to pledge donating more than half of their wealth to charitable organisations.

The Giving Pledge project, announced in August, has been spearheaded by Bill and Melinda Gates and investor Warren Buffet as a way to encourage entrepreneurs to become philanthropists earlier in life.

Zuckerberg is just 26 years old and was said to be worth $6.9 billion in the latest Forbes list of richest Americans. While the Facebook CEO took a publicity hit with the launch of The Social Network movie about Facebook’s rise, he has also polished his image through such actions as pledging $100 million to bolster New Jersey schools. 

Zuckerberg's social networking sidekick Dustin Moskovitz, also 26, has signed on to the Giving Pledge as well, as has AOL co-founder 52-year-old Steve Case and his wife Jean, adding 17 families/individuals to the original list of 40.

Oracle’s Larry Ellison was among the original group of pledges that also included investor Carl Icahn, film director George Lucas and TV mogul Ted Turner. 

The focus to date has been on US donors, but the plan is for Buffett and the Gates family to take the program international.

Zuckerberg in his pledge said that: "People wait until late in their career to give back. But why wait when there is so much to be done? With a generation of younger folks who have thrived on the success of their companies, there is a big opportunity for many of us to give back earlier in our lifetime and see the impact of our philanthropic efforts."

In a similar vein, actor Edward Norton started up a social networking site called Crowdrise focused on charitable giving. 

Among tech firms, Google has been particularly ambitious about charitable giving, donating $2 million earlier this year to support Wikipedia, for example.

Tech industry watchers say that young employee prospects, "millennials," are especially interested in working for organisations that give back to the greater good.

With the tough economy, US charitable giving dropped 3.6% last year to $303.75 billion, according to the Giving USA Foundation, which tracks donations from individuals, companies and foundations.