My cousin posted a video on his facebook that I just finished listening to entitled "The Concept of Race". It reinforces an idea I've had for a long time that "race" is a cultural and sociological reality rather than any kind of physical one.
(1:15, safe for work)
Click to view
He had some remarks that (eta: seems to) debunk a lot of the popular ideas (natural selection/mutation as the reason for skin color variations, etc.), which I found interesting.