Organs for transplantation are a scarce resource. Paying to increase the supply of organs is illegal in much of the world. We review efforts to increase transplantation by increasing the supply of available organs from living and deceased donors. Progress has been made in increasing the availability of living donor kidneys through kidney exchange. Recent legislation in Israel aims at encouraging deceased donation by awarding priority for receiving organs to registered donors. We also explore the manner in which organ donation is solicited and present evidence to suggest that some recent movement towards "mandated choice" may be counterproductive.