What effect is used in this image?
Knew this style looked familiar. Took me whole day to remember what plugin it was.
( Not 100% sure the same plugin was used in your example image, but it's at least very similar )
Example of an image made with Fractalius:
Tutorial for using fractalius:
http://techfleece.com/2011/01/30/fractalius-tutorial/ - Had a second glance of this tutorial and you'd probably find better ones with google.