Friendly neighbors, family-run businesses, and quaint restaurants serving comforting diner fare--these are the images conjured up by the phrase "Main Street USA." Even in this fast-paced era, many small towns have held onto their historic roots and preserved their central thoroughfares. From a harbor town on the west coast with ornate Victorian architecture, to Key West's colorful Duval Street, visitors can find unique cultural attractions and warm, welcoming communities in small towns across the country. A few steps along each of these main streets prove that small-town America is alive and well--and can hold its own against larger, neighboring cities. Here are our picks for America's best main streets.--Emily Wasserman