My best friend lives in Portland, Oregon (where there is not a lot of integration). One time when her son was about 3, he pointed to a black guy and exclaimed, “Look, mom, a basketball player!” My friend, of course, was very embarrassed.
I don’t have any particularly funny stories myself, though I’ve noticed that my son (21 mo) will point to people of different races and call them the name of someone we know who’s of that race. For example, we have a very dark-skinned jamaican friend and whenever Sid sees a dark-skinned man, he’ll point and go, “Dino!” When he sees an Asian girl, he’ll point and say, “Pim.” (after a friend’s daughter). One time he pointed to an underwear model in a Target ad, a pretty coffee-colored female model, and said, “That’s Marsha” (his trinidadian babysitter). I later showed marsha the ad and she thought it was funny (and was a bit flattered). Sid has also called a red-headed kid “Malcolm” (his cousin), so it’s not strictly a racial thing.
Another interesting point is that we share a babysitter with another family whose son is half-black and half-white but looks black. My son is blond and white. We have a double-stroller for the sitter to take the boys to the playground, and people (adults) regularly ask if the boys are twins.