PALO ALTO, California — Facebook added Skype video calling on Wednesday for the hundreds of millions of users of the world's leading social network.

Facebook co-founder Mark Zuckerberg unveiled the new video calling feature during an event at Facebook headquarters in Palo Alto.

"We think this is awesome because we're using the best technology that's out there for doing video chat with the best social infrastructure that's out there," Zuckerberg said.

The Skype feature came with an improved group chat feature which allows for a multi-person conversation and had a simple camera icon that could be clicked for instant one-on-one video calls with friends.

Zuckerberg also announced that Facebook now has more than 750 million users.

The Facebook-Skype partnership debuted as Zuckerberg playfully proclaimed the start of a "launch season 2011."

"We've been cranking on projects the past six months and have a lot of fun stuff to roll out," Zuckerberg said.

He portrayed online social networking as being at an inflection point where its momentum is unstoppable and said now Facebook's focus is on fun or functional software applications that can be built on its platform.

"There is this clear arc where the world generally believes (social networking) is going to be everywhere," Zuckerberg said. "In a matter of time it will be billions, whether it is us or somebody else doing it."

He expressed hope that Facebook would hit the billion-user mark.

As ranks of social network users grow, the number of updates, pictures, videos and other content shared is rocketing, according to Zuckerberg.

"We have 750 million users now and it is still growing quickly," he said. "But the thing growing faster is the amount of sharing per user."

The amount of content shared at Facebook has soared to four billion things daily from less than one item a day in the year 2004.

Along with building its own programs to enhance the social network, Facebook will work with entrepreneurs and partners such as Skype.

"It is really gratifying to see this product on the leading social network out there," said Skype chief executive Tony Bates. "There is no greater place to get to the Web than inside Facebook; one click.

"This makes a lot of business sense as well," Bates continued. "We want to be as ubiquitous as possible and great things will happen from there."

Skype is added to Facebook with easily installed Web browser "plug-in" software and no financial deal was struck between the companies in the arrangement, according to Zuckerberg.

Plans to add Skype to Facebook began before Microsoft announced in May that it is buying the Internet voice and video leader for $8.5 billion dollars.

Bates said that he and Microsoft chief executive Steve Ballmer paid a call on Zuckerberg after announcing the acquisition plans at a press event in San Francisco.

"We have a really good relationship with Microsoft," Zuckerberg said, turning to Bates during the press conference.

"Now that you are owned by Microsoft it gives us a sense of stability that we can trust," he continued.

Bates pointed out that Microsoft's purchase of Skype is still pending approval by regulators.