If you thought the Tempurpedicâ„¢ mattress was the last word on healthy and comfortable rest, the Swedish have produced a sharp alternative based upon an old, tried and true style of torturous relaxation.Welcome back the bed of nails, 21st century-style.Power-napping at the office. Note that books can be propped upfor reading by carefully inserting them within the spikes.Caution: Always take care when turning pages.Those who enjoy reading while reclining, particularly at bedtime, may find that the new nail beds require a period of adjustment before curling up with a good book can begin. Words on the page assaulting the eyes...