GREAT BARRINGTON, Massachusetts (Reuters) - A walk down Main Street in this New England town calls to mind the pictures of Norman Rockwell, who lived nearby and chronicled small-town American life in the mid-20th Century. So it is fitting that the artist's face adorns the 50 BerkShares note, one of five denominations in a currency adopted by towns in western Massachusetts to support locally owned businesses over national chains. "I just love the feel of using a local currency," said Trice Atchison, 43, a teacher who used BerkShares to buy a snack at a cafe in Great Barrington, a town...