While posting the recent soda vs. pop maps I remembered seeing this several years ago. A researcher at UWM (or Harvard, I get the two confused) created an online dialect survey and posted the results in the form of maps. THe results show that some are regional, some are not.
For instance, if you look into how people pronounce the word Pecan, residents of the low country of South Carolina say PEE-can pie. But the maps show that to be a more widespread usage than you might have thought. Living near Route 1 I will admit to struggling with the multiple ways I say route, this map shows that it is different here than where I grew up. But I wasn't nearly as aware of how many choices there were for your old fashioned tennis shoes. Did I miss the map for nucular vs. nuclear?