There are many ways in which survey research can be inaccurate, but one would not think that "where do you live?" would be all that open to interpretation. This interesting piece by Daily Kos writer David Nir, shows the dilemmas that can confront survey researchers.
Daily Kos/SEIU Station of the Nation Poll: Where are our respondents from?
The graphic in the article (above), places the dots based on the Area Code and Zip Code of the respondent, the color of the dot is based on where the respondent SAYS they are from (Northeast, Midwest, South and West).