I am currently clustering hundreds of markers on my google maps. Many of the markers are based on geo-coded addresses, which at times only resolve to the city level. Normally i will end up with lets say a few hundred addresses all with the same lat lon for example in the middle of New York City.
I know about the Marker Clustering in google maps, however when all the markers have the same lat long, you loose the ability to click on each marker, and bring up a popup.
How can I manage these markers in such a way when you zoom in you can still tell how many markers there are, and still click on them?
Look at the OverlappingMarkerSpiderfier
See this post on integrating it with MarkerClusterer