Many fantasize about dramatically changing their lives -- living in accordance with their ideals rather than the exigencies of job, bills, and possessions. William Powers actually does it. In his book Twelve by Twelve, Powers lived in an off-grid tiny house in rural North Carolina. In New Slow City, he and his wife, Melissa, inhabited a Manhattan micro-apartment in search of slow in the fastest city in the world. Here, the couple, with baby in tow,...