I did some additional playing around with Google Maps.
In this version, I created (actually lifted) a custom heart icon for the markers to display on the map for some favorite locations at WDW. I did not worry about transparency nor altering the underlying shadow. Why a heart? Because the bright red offers good contrast.
I added logic to display the overlay window (i.e., popup) when clicked on. Once open, you can click on the simple name of the ride to be taken to that page. I declined to spruce it up further for this demo.
You can view it in action at http://wdwescort.com/other/maps/maps_example2.html, and then get the page source to roll your own. Please note that if I move it later, I will add a comment.
It appears in the browser as follows: