Hunchblog does a really cool infographic summarizing a survery confirming a lot of the usual stereotypes of PC users v. Mac users. One question they asked, though, was fantastically insightful:

Both sides are, of course, correct. From a set of “all matter in the universe” or “all living things on Earth” any two human beings will be vastly more similar to each other in every way that matters than they will be similar to anything else. But from a set of “all human beings” those minute differences become far more pronounced.

I believe that how you frame this question explains a lot about how you see the universe and conceptualize life, society, and politics, and has a lot of explanatory power.