I am using markerCLusterer V3 on a db file from Filemaker to generate a (semi-live) map of current delivery locations, based off of addresses. Grabbing the lat/long from Go
var markerClusterer = new MarkerClusterer(map, myMarkers, {
maxZoom: 15,
zoomOnClick: false
});
//zoom 0 corresponds to a map of the Earth fully zoomed out, 20 is closeup
//markerCluster goes away after zoom
//turn off zoom on click or spiderfy won't work