A few years ago, promised cures for baldness, impotence, and old age shared a common image as fraudulent and vaguely pathetic, the illusory straws grasped at by the desperate and gullible. Now, with Rogaine and Viagra offering relief to the hairless and the limp, it's even starting to look as if treatments for aging may offer hope to the wrinkled. That has produced both excitement and, from some, unhappiness. I've written columns on the subject over the past couple of weeks. Recently I interviewed (via email) the influential Cambridge University biogerontologist Aubrey de Grey. De Grey is working on what...