You're about to download the detailed USA-Cities databases.

Download either the ZIP file or some (or all) of the separate PRC files:

Download
ZIP (<500KB)
PRC files: AK AL AR AZ [CA1+CA2] CO CT DC DE FL GA GU HI IA ID IL IN KS KY LA MA MD ME MI MN MO MP MS MT NC ND NE NH NJ NM NN NV NY OH OK OR PA PR RI SC SD TN [TX1+TX2] UT VA VI VT WA WI WV WY

After installing these databases you'll be informed on the name of your caller's city, e.g. "Los Angeles", "Nashville", "Seattle".