The Ascent of Money, by Niall Ferguson

Niall Ferguson is an undeniably smart guy -- he's written about a broad range of global topics quite convincingly (Colossus, for example, on the American empire). So I was happy to pick this history of financial systems up -- I read it more or less in tandem with Krugman's book.

The number one lesson from this book is this: financial systems collapse all the time. It happens in every era in every geography -- which highlights why it shouldn't be such a surprise that our own system is under serious strain right now.

Wonderful history of financial systems, and was great to read alongside Krugman, for a taste of contrasting (but both helpful) views.