Have a look at the IP Geolocation Views & Maps module. Partial quote from its project page:
Despite what the name may suggest, IP Geolocation Views & Maps (IPGV&M) is first and foremost a mapping engine.
The module makes it very easy to create Views-based mapping solutions using the map renderer of your choice (Google, OpenLayers or Leaflet) with any location storage module of your choice, e.g.:
This allows you to bring together modules and feature sets that without IPGV&M you would not be able to combine.
Like beautiful animated marker clustering on Google or Bing or Mapbox ... any of various map providers.
But more importantly IPGV&M adds some features you won't find as conveniently packaged elsewhere.
These include marker differentiation based on field values or ranges (2nd screenshot) with or without font icons, various centering options, super-imposing the current visitor's location, allowing multiple content types to be displayed on the same map, full screen button and mini-map inset (bottom screenshot), polygon support (Geofield), marker tags and tool tips and cross-highlighting of associated content on the page when markers are hovered (and vice versa).
And the Set my location block allows your visitors to locate themselves on the map, either automagically --via the Wifi/GPS device on their mobile-- or by typing an address or landmark, like "Eiffel tower" (bottom screenshot, upper left corner, click to enlarge).
Follow this step-by-step tutorial to create a handy store locator with proximity search, from a list of addresses in a spreadsheet. You'll learn about the Feeds and Display Suite modules too!
Finally IPGV&M provides a set of visitor location retrieval technologies, both IP and HTML5-based, so that you can track where past visits came from and where current visitors are located, superimposing their moving positions as markers on your maps.
Head over to its (impressive) project page for even more information about it.
