Since most donors are dead, an obvious solution is to enlarge the pool of dead people. Most potential donors and their relatives believe that doctors take organs only from brain-dead people. However, redefining death as what happens when your heart beat stops, not when your brain waves flatline, will increase the number of American bodies available for organ harvesting by 22,000. This is an option backed by the US Institute of Medicine in a report earlier this year. Strong support from the British government has increased the number of "donors after cardiac death" by six-fold in the last 15 years. Not all doctors agree with this. Like Lazarus, some patients do recover after their breathing and heartbeat have stopped. However, more and more hospitals are using this definition -- and even expanding it. Just to make sure that the patient is really dead, transplant surgeons used to wait 10 minutes. This interval is dropping to 5 minutes, and three American centres are using a two-minute interval.

There are other options, too -- all highly controversial. The Institute of Medicine baulked at paying organ donors, but a number of bioethicists, libertarians and free-market conservatives contend that this is the only way to meet the shortage. "I resisted all market mechanisms because of the risk of injustice," says Robert Veach, of Georgetown University. "I think we've waited long enough. There are too many people dying. I think it's time to begin limited experiments with cash payments." Sally Satel, a doctor and well- known conservative pundit, wrote in the New York Times earlier this year that repugnance at selling body parts is outdated. Markets for human eggs, sperm and surrogate mothers already exist and are no longer controversial, she argued. What's different about organs?

With this in mind, and no doubt its political battles as well, a task force of the International Society for Stem Cell Research has issued draft guidelines. These insist on informed consent for this uncomfortable and potentially fatal procedure. But they leave the door open to remunerating women for the time, discomfort and trouble involved in egg donation. The chair of the task force, Insoo Hyun, of Case Western Reserve University, argues in the leading journal Nature that local ethics committees will act responsibly in setting compensation at a level which constitutes fair compensation, but not an inducement.

Nature's editorial in the same issue is sceptical of Dr Hyun's confidence in ethics committees and points out that the health risks of ovarian stimulation are still not clear. There is some evidence that the fertility drugs used in IVF and egg donation pose long-term risks of cancer. Researchers say that longitudinal studies are needed, as the cancers may not appear until women are in their 50s or 60s. However, as Nature journalist Helen Pearson remarks, "it's unclear who will drive the effort, particularly when private fertility clinics may have little interest in finding out the potential risks of the drugs they use."

Hybrids have been created in several experiments around the world over the past few years, but the SCBH questions their scientific merit. It warns that creating embryonic stem cells from the enucleated eggs of cows or rabbits filled with genetic material from a human cell poses "profound medical risks" and, in any case, would yield hard-to-interpret results.

Public interest in the grotesque shows has apparently spurred a murky mini-industry in China. The bodies displayed by Premier Exhibitions are created by Dalian Medical University of Plastination Laboratories, according to its website. Where the bodies come from remains unclear despite protestations from Premier Exhibitions that it uses only unclaimed Chinese bodies given to medical schools by police. Human rights groups allege that the bodies of executed prisoners and the mentally ill are being used as well.