The New York Times has a 25-question, multiple choice survey about word usage and pronunciation (e.g., "How to you pronounce "aunt?").
I took the test and the pattern my dialect most closely matches is from Stockton, CA, Denver, or Aurora, CO. I was born in Denver and grew up nearby in Golden and Boulder. How well does the survey do in pinpointing where you grew up?
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects