Let's say Google doesn't offer just the right icon you're looking for for your Google Maps app. What's a geek to do? Well, create your own icon, of course. This is trivial to do.
What's not trivial to do is to get the shadow image right. And attempting to use a Google Maps Icon (GIcon) without setting a shadow image will break your app.
Along comes: shadowmaker that does exactly what you want it to do: it takes your icon and generates the appropriate shadow image.
What a time saver! And the app will even spit out the code you need to use to get the settings on the icon just right. If you do Google Maps, you need this site.
Check out my first Google Maps app in the wild here.