Also note that Apple fans tend to stick to urban areas for the most part -- there is a nice big oasis of Mac fans in Colorado and Nevada, but we wonder if the lower population density in those places makes the results a little weird. Also notice the lack of Apple ownership in the south -- Louisiana is not Mac country, apparently.
You can check out the full list of all 206 cities here. You'll need to register to download the results (PDF), but it's worth the look. For those of you who don't want to wait, the top five Mac-centric cities are: San Francisco-Oakland-San Jose, CA; Boston, MA; San Diego, CA; New York, NY; and Washington, D.C. And since it's my second-home, I'll list the sixth, too: Chicago, IL.