Maphead is the perfect choice for teen map nerds, and it might just be charming enough for those with a more general interest in geography. As Ken Jennings points out, the National Geographic Bee has 5 million participants annually. 13,000 schools hold mini-bees every fall.
Where some might questions the future of maps now that GPS is widely available, Jennings sees “a digital map revolution” that is making them cool again. (From his interview with Publishers Weekly titled “The Poetry of Maps.”)
For a little fun, @KenJennings sends out a Maphead Quiz of the Day on Twitter.
Tangentially related, I’m taking this chance to recommend another book. Final Jeopardy: Man vs. Machine and the Quest to Know Everything by Stephen Baker (HMH, 2011) relates the story of the men at IBM who created Watson, the computer created to beat Jennings and the other top Jeopardy champions. Baker makes this scientific challenge into a suspenseful story; even the minutiae of computer programming is interesting.
JENNINGS, Ken. Maphead: Charting the Wide, Weird World of Geography Wonks. 288p. maps. reprods. index. Scribner. 2011. Tr $25. ISBN 978-1-4391-6717-5. LC 2010052219. 
Adult/High School–Jennings, renowned for his record-setting run on “Jeopardy,” takes readers on a tour of various geographical obsessions. Though easily readable as a narrative, the book is structured as a series of essays on a range of topics: efforts to improve American geographic illiteracy; antique map collecting; geography bees; geocaching; and more. It was clear when watching “Jeopardy” that Jennings comes by his own trivial knowledge honestly—not by endless rote memorization, but through genuine curiosity in a seemingly endless number of topics–and it is this infectiously insatiable curiosity that drives the book. For the author, trivia of all kinds is a means to an end, never an end to itself: for geography, that end is a better understanding of the world, and (perhaps) a chance to improve the state of the world. Indeed, Jennings is more disturbed by those he encounters who have lost track of why geography is important than by those with no geographic knowledge at all. Even so, he clearly understands the workings of the obsessive mind, and he never condescends to those who are driven, for example, to find every geocache in a 10-mile radius. And as he repeatedly emphasizes, there are many more of these geographical obsessives than one might think, and most of them caught the bug as children looking at maps and globes. So even though, as Jennings states, teen geography buffs may be a bit embarrassed by their hobby, if they can get their hands on this book, they’ll find a whole world of like-minded geographers.– Mark Flowers, John Kennedy Library, Solano County, CA