Republished from Google Visualization.
Overview: A geomap is a map of a country, continent, or region map, with colors and values assigned to specific regions. Values are displayed as a color scale, and you can specify optional hovertext for regions. The map is rendered in the browser using an embedded Flash player. Note that the map is not scrollable or draggable, but can be configured to allow zooming.
We have two examples here: one that uses the regions display style, and another that uses the markers display style.
The regions style fills entire regions (typically countries) with colors corresponding to the values that you assign. Specify the regions style by assigning options['dataMode'] = ‘regions’ in your code.
The “markers” style displays a circle, sized and colored to indicate a value, over the regions that you specify. To use markers, you must include the following Google Maps API script with a key, unless you specify locations using latitude and longitude values.