Northwestern Memorial Hospital has a good video on its living donor program
here:
http://www.nmh.org/nmh/transplant/video.htmAccording to the video, about a third of their living donor transplants
involve non-related donors. The featured non-related donor, who gave a
kidney to a friend, didn't know he could even be a donor to his friend until
he heard a news report about someone who'd answered an ad from a woman
seeking a donor.