I've long been a decorative smoker. One daily roll-up hasn't imperilled my health much, and it's rescued me from the ranks of the self-righteous. I've relished the dash of badness, but my indulgence has come at a price: complicity. My more heavily addicted husband has smoked from the age of 19. So long as I join him in the odd postprandial drag, I'm a bad influence. Last month I switched to an e-cig. I'm a convert. Sleek, black, and easily confused with a fine-point felt-tip, this newfangled "nicotine delivery system" is dead cool. The gently warm vapour ingeniously replicates the...