Has research into the aerodynamic properties of non-smooth surfaces suggested any promising directions for future aircraft design? As you might gather from Can planes benefit from Mitsubishi&#39;s Air Lubrication System? I'm interested in what possibilities there are for radically different approaches to aircraft body surfaces.

Aircraft body surfaces appear to be as smooth as possible, but not all things that fly well are smooth:


golf balls are dimpled (see the very interesting discussion of Is a golf ball surface a good idea for wings or fuselage?)
birds are feathered
sharks have placoid scales (yes, I am aware that sharks don't actually fly through the air...)


Has scientific or industry research indicated useful possibilities in new surfaces for aircraft body skins - or maybe alternatives to skins altogether?
Non-smooth surfaces are already used, particularly in some Military Aircraft. If you've ever run your hand down the fuselage of an FA-18 Hornet you will find the surface is quite rough, much like the skin of a shark. At lower speeds very little is achieved, however at higher speeds small bubbles of air buildup in the indentations of the skin thereby creating an extremely slippery surface.  

Take a look

Take a look here too

I'm certain my terminology is not correct, sorry about that. I would have put this all into comment, but I'm not allowed yet.