Emergence was the best science book I found in 2001. It provides you with the best overview over self-organizing systems in different areas, from ants to cities, from software to the human brain.. And I found the book very easy to read and understand, though I learned a lot about very complex structures.
The book starts with the explanation of the specific behavior of ants and how this theoretical model of self-organizing systems was built. The very old and new components were feedback loops, with are necessary for self organized systems.
Then the author is looking for the same complex structures in other biological environments like body-cells and the human brain. But that was not enough. He also is looking in social environments like the guilt system in Europe or modern cities and their living structures. At the end the newest researches for software programming leads you to development in the Internet and the working with computers. It is very astonishing to see, were the future may go.
Beside the actual facts, the book also explains the development in those scientific areas over the last decades and shows us the ways the scientists were gone.