The lab at school was always a mysterious place. Most particularly, the shelf that contained the specimens. They were distributed in jars lined up inside a shelf whose glass doors were never opened. There was a strong smell of formaldehyde. One jar regularly caught my eye: it was of a small human foetus, its large head curving round, hanging suspended in some yellow liquid. It was an object of awe and dread, a dead thing swaying gently in its opaque, watery space. It never occurred to me that it had other resonances: a grieving mother, a disappointed family. It was simply a specimen. Once you were dead and in a lab, that's what you were.

Not any more. Ever since the Alder Hey disclosure, when it came to light that organs of children had been stored for research without adequate parental consent, body parts have been the subject of tender concern. It seems that when people signed a consent form that told them the consequences might involve "the retention of tissue for laboratory study" or even "for the treatment of other patients for medical education and research", they didn't take in that this might mean ending up as a specimen on a laboratory shelf.

Would that be such a terrible destiny? After all, the other options aren't particularly attractive: "Ashes to ashes, dust to dust" certainly carries the poetic notion that we are returning to the earth from which we sprang. But England's leafy country churchyards are crowded these days. You have to have family connections or pull strings to get in. Otherwise, there's cremation and the scattering of ashes around a rose tree, perhaps, or into a favourite river. I know someone - the relation of a victim of the Munich air disaster that killed Busby's Babes in 1958 - whose ashes are scattered on Man United's ground (apparently, it's considered a great favour - there are many requests and only a few are chosen).

The idea of death at sea has its appeal, made lyrical by Shakespeare's imagination: "of his bones are coral made..." But you need to die either overindulging on a luxury cruise or being flung from a yacht in a high gale, and I don't fancy either.

That leaves the option of doing something useful with what remains of you. I know people walking around today with bits of other people fully functioning inside them. One has someone else's heart, the other a liver. Both organ donations came in the nick of time to restore my pale and waning friends to the vigorous and creative people they had been before their illness struck. One even believes he acquired, along with his new liver, a deeper and more thrilling taste in music.

Both live with a sense of daily gratitude for what has happened. That can't be such a bad destiny for bits of what was formerly you. There may be even more exotic destinations. JG Ballard writes in his autobiographical The Kindness of Women of the tender, even loving relationship he struck up as a young medical student with the female cadaver he was dissecting. (Make allowances: the man's a genius!)

So what arrangements have I made? Clearly, it's important to sort matters out while your step is still sprightly, because for close relations bereavement is no condition in which to make heart-wrenching decisions. Have I decided? No. I am stopped in my tracks by an appalling thought. My body and its available spare parts are probably too old and run down to be much use. My liver has been given a rough time by a lifetime's pleasure in wine; a taste for sirloin steaks and cream teas has probably furred up my arteries. I smoked until I was 40, so the lungs will be no good to anyone. Besides, I read that heart, liver and lungs are only likely to be useful until the age of 65.

That leaves the kidneys - the age limit there is 75. I used to carry a kidney donor card, but it seems to have gone missing. There was a proposal to make donation automatic, so that you only needed to make arrangements if you wanted to opt out and take your kidneys with you. That idea has been rejected, it seems. So I'll need to forage for that old card again. The best news is that there is no age limit for the donation of corneas. So perhaps one day far hence, I shall still be gazing fondly across that candlelit table, at someone else's Valentine. Gruesome? Well, it's better than being in a jar on the laboratory shelf.