Apparently there is some sort of marketing exercise taking place later today known as a "football game." The idea is for the biggest corporations in the country to come up with their most clever advertisements of the year and showcase them before an eager national audience. There are also odd breaks between ads which feature strangely homoeroticized violence. Anyway, here's a map from Common Census which depicts the US in terms of football team allegiance.
Each smudge of color represents the most popular team in that region. It's based on the responses of participants in their online survey; there's a fair amount of noise in the data, but still, it's actually a pretty interesting way of mapping the sphere of influence of various cities.