The MLA (Modern Language Association) has an interactive language map of language communities in the U.S. based on the 2000 Census data (with updates from 2005) at:
In addition to the basics, you can find information on language communities by state, county and even zip code. If you really want to check it out, I recommend viewing data from the Los Angeles area. It’s probably as linguistically diverse as New York.
As a fun class exercise, I just took the basic U.S. map showing concentrations of non-English speakers (bluer = higher percentage of English speakers) then asked students to guess which language communities were being represented. Another fun exercise would be to have people look up the third largest spoken languages in different regions. Overall in the U.S., the third largest is Chinese, but in Pennsylvania it’s German (and Tagalog (Phillipines) in California).
P.S. I should note that today the map is hanging when collecting data, but Internet speeds have been slow in general…hopefully it’s a temporary glitch. If the map isn’t working, you can retrieve the raw data by clicking “Tabular View”.