Organs and Funerals
The Nuffield Council on Bioethics has suggested that the NHS could pay for the funerals of those who donate their organs. (News reported here.)
I find it somewhat curious that they draw a sharp distinction between this move and payment for the organs. Presumably this incentive is only likely to increase donation rates insofar as it is regarded by donors as a payment. So either it's a payment and thus undermines altruism and raises worries of exploitation, or it's not a payment but it's questionable whether it will really increase donation.
(Personally, I'm not convinced that donation need be wholly altruistic and am therefore open to the possibility of incentives.)