Creating coffee creme effect in Photoshop CS5

This morning as I was pouring cream into my coffee I watched the result of my stirring the new addition. It was interesting and I began wondering if the effect could be created in Photoshop. Searching the web in pursuit of a tutorial I discovered this post at Photoshop Atoms. He also gives you the source files if you are willing to give him your email address. I say "he" but I really don't know. A quick glance around for someone to credit turned up nothing.