Scout, Question: How many minutes of longitude does it take to answer a trivia question?
Answer: It depends on if you know the answer, how quickly you can blurt it out, and how fast and in what direction you are traveling.
Check out this GPS-enabled Road Trip Trivia Tour http://travelbygps.com/premium/minnesota/hwy_61.php of Highway 61 along the Mississippi River in Minnesota.
It's a free download in Garmin TourGuide formatted file (.gpi) which includes audio narrative and visual images, or free GPs eXchagne (.gpx) file without the audio and pictures.