"Guns, Germs and Steel. A Short History of Everybody for the last 13,000 years" by Jared Diamond

This is a really cool book. It sets out to provide an explanation for things like why white europeans conquered the Americas, rather than american indians conquering Europe. This might make it sound like a racist 'white supremist' book, but it's not at all. Everything boils down to things like plant and animal distribution on the different continents and the shapes of the continents!

If you've ever wondered why have domesticated cows and so on yet not kangaroos, this book tells you why. It also explains why the Aztecs caught diseases from the Spanish conquistadors, yet had no diseases to give back.

The book is really well written, and doesn't leave you puzzling about what he means, like many nonfiction books do. I thought it was really interesting, and if you've ever wondered about 'what if' historical scenarios then this is the book to read.