It occurred to me that the North-East, Mid-West and South/West looked vaguely reminiscent of American political party affiliation data by state, so I found this Wikipedia map of the gubernatorial election results data from 2010:
Well, a slight correlation can be discerned, anyway - California may be favouring Android overall, but Mashable's article did report that there are iOS-heavy cities (to be specific, they were reported as San Francisco, San Jose, Modesto, Oxnard, Santa Barbara, Chico, Santa Cruz, San Luis Obispo and Napa).
Given my personal history in Massachusetts and the fact that most of my friends (and colleagues) are iPhone owners, one might think I'd also jumped onto the iOS bandwagon. Apple had also been the most popular smartphone manufacturer in Japan.
However, when I finally joined the smartphone using populace this past May (closely coinciding with the launch of this blog, actually), I'd picked an Android phone. Articles like this one, reporting from Bloomberg, piqued my curiousity sufficiently for me to make this choice, when combined with the cumulative gaffes surrounding Apple's iPhone (for design issues and pre-ordering of the 4th gen, to cite just two instances.)
In any case, I'm still hoping my spouse will upgrade to an iPhone 5 not too far in the future: his Nokia is on its last legs, and then I'll be able to make some personal comparisons to the usability of these OSs.