perhaps it is just me but I just tried the example code from
http://code.google.com/apis/visualization/documentation/gallery/genericimagechart.html
and it didn't work.
Example:
<html>
<head>
<script type='text/javascript' src='http://www.google.com/jsapi'></
script>
<script type='text/javascript'>
google.load("visualization", "1.1", {packages:["imagechart"]});
google.setOnLoadCallback(drawChart);
</script>
<script type='text/javascript'>
function drawChart() {
var dataTable = new google.visualization.DataTable();
dataTable.addColumn('string');
dataTable.addColumn('number');
dataTable.addRows([
['DZ',0],
['EG',50],
['MG',50],
['GM',35],
['KE',100],
['ZA',100],
]);
var options = {cht: 't', chtm: 'africa', chco: 'FFFFFF,EEEEEE,
000000', chs: '440x220'};
var chart = new google.visualization.ImageChart
(document.getElementById('map_div'));
chart.draw(dataTable, options);
}
</script>
</head>
<body>
<div id='map_div'></div>
</body>
</html>