I’m trying to display photos as markers on Google Maps. This is no problem by redefining the marker as an image, but I want to put some sort of border or shadow to make them stand out better. Something like the Google photos would be best, but I guess this is too complicated, if at all possible. A simple 1px solid border would do fine. One option is to actually change the image, but this is not an option. Also, the images are different sizes so I can not put a black image as the shadow (1px larger than the original).
Here is the idea:
CURRENT:

LOOKING FOR:

EVEN COOLER:

IDEAL WORLD:

Is this possible?
Have a look at the Rich Marker v3 library demo (the actual library) which allows to use custom html as a marker.
Setting a marker html of
and clicking the toggle flat (an option in the library api) would do what you want.. you alter the image src of course 😉
for more libraries look at http://code.google.com/p/google-maps-utility-library-v3/wiki/Libraries