The corner of Ludlow and Rivington, a slightly run-down intersection on Manhattan's Lower East Side, is not a place where you would expect to find a profound statement about the relationship between public art and memory. Yet every night for three weeks last October, as a thin blue laser beam silently wrote out the dreams and memories of the neighborhood's ethnically mixed inhabitants on tenement walls, otherwise nondescript buildings became reanimated by history. Visitors walk ed up and down the street, talking and pointing to the moving beam as it scrolled across the wall in five different languages. "I remember the Jewish church on Rivington. I was 17 years old when I saw it for the first time.