Is there an open source data classifying Urban, suburban, and rural blockgroups? I am specifically looking for the urban continuum data for Hillsborough County, Florida. I know that Nielsen Claritas has developed a specific variable named urbanicity for the purpose of classifying blockgroups. However, it is not free. Just wondering if I can get similar data from any other open source?
you can probably find what you are looking for inside the census summary files
file layout from http://www.census.gov/prod/cen2010/doc/sf1.pdf#page=18
some code examples of how to work with those files:
As Anthony suggested, there is an urban/rural designation available in the SF1 file. Rather than dealing the the huge, raw datasets, you can go to the Census's American Factfinder site and just download the columns of interest for Hillsborough County only (you should be able to find a table there called "Urban and Rural". This will be a flat file. If you need shapefiles, find them here: http://www2.census.gov/geo/tiger/.
As a point of clarification, the Census Bureau doesn't use "suburban" as a classification. More on how to derive that can be found in various answers to this earlier question.