Someone starts by naming a place (city, town, village, province, state, country, continent, and so on), the next person must name a new place starting with the last letter of the previous place. For example:
Rio de Janeiro
...you get the idea.
The game ends when someone can't think of a new place within a reasonable time. The only hard and fast rule is that you can't repeat place names. As I got older and realized it was really easy to stump people if you said "Ajax", I also added the rule that you weren't allowed to say places that ended in "X". I just had too much fun playing the game and never wanted it to end!
Then, on a bank holiday weekend a few years ago, we decided to drive from Oxford to Cornwall with some well-traveled friends. We started playing the game and decided to play it as long as possible. Much to my husband's chagrin (who had been tasked with driving as the only one with a UK licence), the game lasted the entire weekend and he has refused to play it since.
Once JR is old enough, I plan on secretly teaching him the game, because I know that daddy won't be able to refuse his son's sweet puppy dog eyes when he begs to play!
What fun car games do you play with your kids?