After reading Freakonomics some time ago, I had decided it was time to read another book on economics for the layman (yes, I've encountered economics courses during my studies, but was thinking about something that my wife, who has not often come across such issues, could also read). Therefore, I picked up this book by Tim Harford, one of my favourite FT columnists. His blog, linked above, is also a blast.
I thoroughly enjoyed the book myself, and I would definitely suggest anybody with a little bit of curiosity to pick it up. The chapter on underdeveloped countries, in my opinion, should be read by pretty much everybody who cares about these issues, especially those of us who are from or live in one of those places.