Google Maps API easily allows to add custom markers to a map (see documentation here). Should you encounter the problem of your custom markers not being clickable, even though you set z-index to a very high value, the solution could be the following:

simply set the API version parameter in the Google Maps Api url to 3.3 .

The script url you include in your page to display a map would then look like this:

“http://maps.google.com/maps/api/js?sensor=true&v=3.3″

This resolved the issue for me.