Map with Checkboxes

                                          http://www.usda.gov/maps/maps/kyfcompassmap.htm

This map, "Know your farmer, know your food" , allows the user to explore farming in the U.S..  My favorite feature of this map is the farmers market locator.  If the user zooms in close enough each point becomes a button.  When clicked on, a pop-up appears that describes the market and contains a link to the market website.  Information pop-ups also appear for other layer points.