toss back a few, let your guts do the restIf you've ever wanted to know exactly how a hangover works, grab a couple-weeks-old issue of the New Yorker and school yourself on this age-old problem following a night of good cheer. "The liver, in processing alcohol, first addresses itself to ethanol, which is the alcohol proper, and then moves on to methanol, a secondary ingredient of many wines and spirits," explains sober reporter Joan Acocella -- are you still with me? "Because methanol breaks down into formic acid, which is highly toxic, it is during this second stage that the hangover is most crushing." Crushing indeed. Our favorite item from this story is the perfect colloquialism for the hangover, from the Danes: "carpenters in the forehead."