Nationally, the unemployment rate fell less than one percentage point from April 2010 to April 2011. But not all areas of the country are the same.

This map, made with ArcGIS, shows all 3,100 U.S. counties, with darker green shades representing counties that saw their unemployment rates decrease over the year. Darker reds represent higher unemployment rates during that time.

It appears that Nevada and Michigan had counties that improved the most (of course, they had the most room for improvement). Idaho and Louisiana have seen their respective rates increase in many counties: 

Source: Bureau of Labor Statistics | Download data