Through the use of thematic maps created by Joshua Katz in the Department of Statistics at North Carolina State University, students get to practice map analysis while also seeing how different parts of the country tend to use different words and phrases for common items. Depending on where your class is located, it might even spawn some heated debate among your students as to the "correct" way to say things. I should know... my classes are always evenly split on "pop" vs. "soda" and "water fountain" vs "bubbler".
Besides being an intriguing discussion topic, it also opens their eyes to the fact that dialects exist and even though people might speak the same language, they could still be speaking differently.
Slides include a bell ringer or warm up question, thematic map images for analysis and discussion, definitions for language and dialect and a wrap-up question.