Full book name: "Out of control: The New Biology of Machines, Social Systems and the Economic World".
In this book the author tries to tackle the difficult subject of complex systems, both natural and human made. Many complex systems are governed by difficult non-linear equations that make complete understanding impossible (this is the basis of the Chaos theory), but yet nature seems to overcome many difficulties in its way to take advantage of the physical laws by building complex and autonomous organisms. The main theme of this book is pondering on the structure of these systems - how they achieve their goals, and how can we learn from them to build our own tools and machines.
The prime tool of the natural world to handle complexity is evolution, and Kelly seems to support the idea that it will be hard for humans to imitate such complex systems without turning to artificial evolution - a point well demonstrated by the advance of evolutionary programming and genetic engineering in the past two decades. Another tool is the "hive mind" - a collection of many small entities, each in itself simple, which in unison create meaningful complexity. The human brain (neurons) and the bee hive (or the ant farm) are good examples for this.
"Out of control" is mostly readable, though at times one can notice it's not very well written. The beginning of the book and its end are quite heavy and take patience to dig through. The middle is more accessible. Also, I wish this book has been written now, in 2006 - in a world of such fast changes, 1994 is too long ago to discuss this subject.