Добавление маленькой дельты будет работать так (этот скрипт написан на PHP):
$random_num_lat = .00065 * mt_rand(1, 10); // delta to the lat value added
$random_num_lng = .00065 * mt_rand(1, 10); // delta to the lon value added
$lat=$row['lat']+$random_num_lat;
$lon=$row['lon']+$random_num_lng;
//now in loop it will be three `enter code here`marker display seperate to each other
while ($row = mysql_fetch_array($query)) {
echo ("addMarker($lat, $lon,'<b>$name</b><br/>$desc1');\n");
}