Conversations over the dinner table with his med-student girlfriend helped Mark Zuckerberg formulate his latest big idea - harnessing the power of Facebook to help eliminate the critical shortage of organs for patients desperately in need of life-saving transplants.

And it was his friendship with Apple founder Steve Jobs, whose life was extended by years following a liver transplant, in part, that spurred the 27-year-old Facebook founder and CEO to help put that idea into practice.

"Facebook is really about communicating and telling stories… We think that people can really help spread awareness of organ donation and that they want to participate in this to their friends. And that can be a big part of helping solve the crisis that's out there," Zuckerberg told ABC's Robin Roberts in an exclusive interview at the company's headquarters.

Starting today, users in the United States and U.K. will be able to add that they're organ donors to their Timelines, and if they're not organ donors, they can find links to official organ donation registries and instantly enroll. "We want to make it simple," said Zuckerberg. "You just put in the state or country that you're from, so that we can help link you to the official registries."

In the "health and wellness" section of users' timelines, users can list their status as organ donors and explain the decision to their friends, in an effort to raise awareness about the need for donors.

More than 112,000 Americans are awaiting organs, and 18 people die every day from the lack of available organs, according to Donate Life America, a nonprofit alliance that is partnering with Facebook.

Zuckerberg, 27, has made a fortune on the idea that people want to share everything - from photos, to the intimate details of their romantic lives.

Yet, Zuckerberg himself is famously private, keeping details of his personal life - not to mention a much-anticipated Facebook IPO - under tight wraps.

In conversation with Roberts, Zuckerberg kept the door on the IPO tightly shut - citing the government-mandated quiet period before the IPO - and saying only "we try to keep very focused on the long term… We'll be judged by how good the things are that we build and whether people like them."

But he revealed some small details of his personal life, lighting up when talking about the dinnertime chats he had with girlfriend Priscilla Chan that helped lead to the donation initiative.

"She's in medical school now," Zuckerberg said of Chan. "She's going to be a pediatrician, so our dinner conversations are often about Facebook and the kids that she's meeting."

Chan told him stories about patients she meets "getting sicker as they don't have the organ that they need."

But there were other stories too, of children who ultimately received transplants. Stories, Zuckerberg called, "unbelievable."

From Chan he learned of one boy in need of a heart transplant. His skin had turned blue from lack of oxygen, but within weeks of receiving a transplant he was out again playing sports.

"How can that not make you happy," he asked.

Chan inspired Zuckerberg to try to learn Mandarin Chinese in one year. That venture, he admitted, was unsuccessful, but he picked up enough to natter with Chan's elderly grandmother.

Zuckerberg said he was further prompted make Facebook an important tool to encourage donors to register following the death of Steve Jobs, whom he called a "friend."

Though Zuckerberg never talked with Jobs specifically about a Facebook donation tool, he said many of the people involved in the project were inspired after Jobs' death.

"That definitely, I think, was something that we all had in mind as we were building this out… His story is just one of many, of people who both were able to have an organ transplant that made his life longer and he was extremely thankful for that," Zuckerberg said.

Facebook was initially developed by Zuckerberg while still an undergraduate at Harvard. The site was initially conceived as place for college students to socialize.

Recently, however, Zuckerberg said he's been surprised by the power of the network and the way users use its tools creatively in times of crisis, like finding loved-ones following tornadoes in the Midwest or the tsunami in Japan.

"People are using the same social tools that they're using just to keep in touch with people on a day-to-day basis to solve these important issues," he said.

The technology behind the donation application, Zuckerberg said, is a "pretty simple thing." But the ability to link people across hundreds of miles and save their lives? That, he called, "amazing."

Both the company and organ donation advocates are hopeful the new tool could change the landscape of the organ donation process.

I think it's possible that we will see an impact over the next couple of years, where we would imagine eliminating the transplant waiting list," said Dr. Andrew Cameron, Transplant Surgeon at Johns Hopkins University School of Medicine.