If you were one of the 6,500 kidney patients in the UK waiting for a donor to save your life how far would you be prepared to go?
You might get lucky. There may have been a person who had volunteered a kidney after they died. But there are still nowhere near enough on the donor list.
Or you may be fortunate enough to receive a kidney from a living donor (those of us in good health can live perfectly well with just one kidney). But only 117 people - motivated by altruism - have come forward to give a kidney in such a way.
And they have to donate their organ into the hands of the NHS for the NHS to choose the recipient. It is done anonymously - you may never know who received your gift of life.
But in the US, desperate patients have found another way and it's persuading hundreds more to volunteer a kidney. They make direct, emotional appeals via the internet.
Some sing, some sob, some put their children in front of the camera to plead their Mummy or Daddy's case. It's strong stuff.
And one of the websites they use is about to launch here in the UK. It's highly controversial.
The NHS and the Human Tissue Authority, which regulates transplants, recognises that the US websites do indeed prompt many more to come forward to donate organs. But is it right that the donor process should become a sort of gruesome X Factor whereby people compete for a kidney, depending on their ability to make a film and pull the heart strings?
Or is it only human to want to know - if you are willing to undergo a serious operation - who the recipient of your kindness will be? And if, ultimately, it leads to more donors coming forward, does it matter?
Already three people a day die on the UK transplant waiting list. As MatchingDonors prepares to launch in the UK, I've been to meet the first British woman to find a donor on an American website, and follow her struggle to get the operation performed here in the UK.
We meet those who are seriously opposed to such a process, and speak to two British women who've given their kidneys to America, just so they can know who is receiving them.
That's all on Tonight: 'The Kindness of Strangers' - Thursday, 7.30pm on ITV1