Riding the early morning Metro North train from Grand Central to Greenwich on April Fool's Day 2006, Luke Anthony briefly pondered the revitalization of some of the once grand Harlem neighborhoods. But then his thoughts turned back to the task at hand: to form a cohesive view of the likely path of the Japanese yen. Was the dollar on one of its patented upward swings that would bring it to 140 ?/$ before long? Or is the past year's dollar appreciation just a brief pause in a longer-term downward march as the record current account deficit drags it to the depths?