Thanks to open-source code and inspiration from Derek Eder in Chicago, we have created a dynamic polygon legend for our search-and-filter map template that draws data from user-friendly Google Fusion Tables. When users click on different thematically shaded background layers, the data ranges magically appear in the legend. Check out the demo that displays schools (points) on top of two polygon layers: median household income and unemployment rates for Connecticut towns. Download the code and build your own with our instructions. It even looks good on a smartphone!