LONDON — Nostalgia ain't what it used to be. In these frenzied, media-saturated times, the lure of a simpler past is more powerful than ever. That may explain the success of "The Dangerous Book for Boys," a deliberately retro tome that has become the publishing sensation of the year in Britain. Exuding the brisk breeziness of Boy Scout manuals and Boy's Own annuals, "The Dangerous Book" is a childhood how-to guide that covers everything from paper airplanes to go-carts, skipping stones to skinning a rabbit. It spent months on British best-seller lists, has sold more than half a million copies...
