Nice one. Its a collection of essays by DA covering the philosophical aspects of the GTD methodology. (my interpretation).
I use it as my cheerleading book. Whenever i need some GTD inspiration, I open any page randomly and the essay (2-3 pages max) seems to hit home. Its a great trick- also works with any book/author you really like.
"Ready For Anything" is a collection of 52 essays, I believe derived from David Allen's "Productivity Principles" newsletter. Each essay is a meditation on some aspect of personal productivity, exploring the deeper principles behind the GTD methodology.
I really like this book. The essays are inspiring and thought-provoking. The book is perfect for dipping in for a quick read and then mulling over what you just read.