Purpose:
To use shadows to enhance your artwork; tell a story; or even interact with your viewer;
To create your own "shadow" photography by setting up items to photograph, going outside and looking for natural shadows in the world, allowing someone to interact with the shadow, or even allowing the shadow to interact with the world.
I really liked how, when angled upward, my lamp made it look like the shadows were shooting towards my fingertips.
This doesn't really count as "good shadow photography" but I loved how the sunset made the shadows of my feet look really blue.
I just thought this looked funny, and it also made me conscious of my old stairs. Regardless, whoever is going down the stairs next should watch out.