Facebook users in the United States and Britain will now be able to show on their page whether they wish to donate their organs.
The hope is that it will encourage more people to register as organ donors.
Nearly 7,000 people in the United States die each year while waiting for an organ transplant and around 10,000 people in Britain are on the waiting list for an organ. With the huge numbers of Facebook members in both countries, the social networking site hopes its foray into social engineering will make a big impact.
An American liver transplant director at a major hospital, Dr Andrew Cameron, called it a historic day and speculated it may well eliminate the problem of people dying while waiting for a transplant.
As well as registering as donors, people are posting their personal stories of why they are donating. Debbie Greenwood from Manchester, 336 friends: "My 5-year-old grandson had a combined liver and kidney transplant 18 months ago, his life is now 100% better and we are eternally grateful to the donor family, whom we have met."
Facebook says the initiative is about making it easier on families, as they are more likely to know their loved one's donor status in advance. It's also about encouraging people who may have thought about it, but not got around to it or who might be inspired to donate if they find out that their friends are doing it. The British site already has nearly 70,000 Facebook likes and climbing.
an organ transplant: transplantasi organ
the waiting list: daftar tunggu
foray: upaya baru yang belum pernah dilakukan
social engineering: rekayasa sosial
eliminate: mengatasi, menghilangkan
registering: menyatakan kesediaan
eternally grateful: sangat berterima kasih
in advance: sebelumnya