Keywords: Four ball async columns, four ball snakes.
This pattern is pretty simple in concept, but can be difficult to control effectively. Practice, practice, practice.
If you need help with your three ball columns, check out this tutorial.
Check out wikipedia if you want to learn more about snakes or columns.
Note: The columns pattern shown here is asynchronous, giving the pattern its slithery look. There are several variations of timing with four ball columns, so play around and see which ones you like.