Missed this link!
   [1]http://www.newscientist.com/opinion/opbooks.jsp?id=ns23539
   Linked
   Albert-Laszlo Barabasi
   $26 Perseus
   Nexus (Small World in Britain)
   Mark Buchanan
   $25.95/18.99 W. W. Norton/Weidenfeld & Nicolson
   America's baseball superstar Yogi Berra has a sideline as a
   man-in-the-street philosopher. His epigram, "It's dj vu all over
   again", sprang to mind while I was reading Linked and Nexus.
   Albert-Laszlo Barabasi and Mark Buchanan deal with the emerging science
   of networks - how they form, how information and matter move through
   them, how puzzling aspects of everyday life can be explained by
   understanding their dynamics.
   What's the message, then? Simply that all networks - -the Internet,
   terrorist groups, multinational industries, interstate highways,
   Amazonian ecosystems - follow the same simple and powerful rules. The
   "science of networks" has sprung up to uncover these rules, and provide
   a firm foundation for the care and feeding of these interconnected
   patterns.
   Curious as to how Google came to be the most popular search engine on
   the Internet or what it would take to dismantle the Al Qaida terrorist
   network? The Barabasi volume will tell you. But if you want to
   understand the spread of infectious disease, how riots form or why the
   rich always seem to get richer, then Buchanan's treatment is for you.
   The mathematician Paul Erds published over 1500 papers with 507
   co-authors before his death in 1996. This prodigious output gave rise
   to something mathematicians call the "Erds number," an integer
   representing the number of steps between Erds and any given
   mathematician. Erds obviously has Erds number 0. Anyone who wrote a
   paper with him has number 1. Anyone who co-authored a paper with one of
   Erds's co-authors has number 2, and so on. A low Erds number is a
   matter of considerable pride among mathematicians, so important in fact
   that there is a Web page devoted to keeping track of the Erds number of
   thousands of mathematicians.
   What is quite astonishing is that almost everyone - even a
   non-mathematicians like Bill Gates - has a very low Erds number,
   typically between 2 and 5. This is a quintessential example of what
   Barabasi and Buchanan call the "small worlds" phenomenon. Basically,
   this web of science is a small world because it is a highly
   interconnected web, in which almost all mathematicians are closely
   linked to each other via a short path of co-authored papers.
   The network of mathematicians and their Erds numbers serves as a
   prototype for just about every human social network - including the
   Internet, as both Barabasi and Buchanan show. Suppose you look at a
   particular Web page and ask how many clicks of your mouse it takes to
   get from this page to any other page via hyperlinks. Barabasi and his
   students actually did this calculation for their website at the
   University of Notre Dame. It contained 325,729 documents connected by
   1,469,680 links. Counting up how many pages had one link, two links,
   and so on, they discovered that the number of pages having a certain
   number of links decreased by about a factor of five each time the
   number of links was doubled.
   These results lead to a simple relationship between the number of links
   in a network and the number of nodes in the network having that many
   links. Called a "power law", this relationship forms a central
   principle by which networks structure themselves. As both authors point
   out, power laws play as important a role in understanding networks as
   the famed bell curve of the normal probability distribution plays in
   understanding the role in statistics of independent random variables,
   such as a person's height.
   Two other extremely important rules of networks are also considered in
   some detail in each of these books. One of these is the "weak link"
   discovered some 30 years ago by sociologist Mark Granovetter. It refers
   to the seemingly paradoxical fact that the most important connections
   for spreading information throughout a network are not the people who
   are most closely connected to you. Rather, the key "connectors" are
   those who form a bridge between the cluster of people you know and
   other, similar clusters of close acquaintances of your friends. Thus,
   the links in a social network are not established at random.
   Instead,they are strongly clustered, and some of the connections are
   more important than others - that is, the ones enabling one cluster to
   link to another.
   These "busy bees" with an uncommonly large number of links to many
   clusters are the people writer Malcolm Gladwell claims are responsible
   for creating fashions and trends. They make deals happen and generally
   serve as agents or middlemen who "tip" things in one direction instead
   of another. The central idea of his book The Tipping Point (reviewed by
   Paul Marsden, 6 May, page 46) is that tiny and apparently insignificant
   changes can often have consequences out of all proportion to
   themselves, accounting for the transformation of unknown books into
   bestsellers or the rise of teenage smoking.
   Both Buchanan and Barabasi give enlightening accounts of both
   Granovetter's and Gladwell's work. Dig in, too, for fascinating
   accounts of the stability of food webs, the formation of "old boys"
   networks, the "new economy", the human genome, and much, much more.
   Both books are extremely well-written, entertaining accounts aimed at
   the intelligent lay audience. The overlap is inevitable: Barabasi and
   Buchanan employ the same anecdotes, talk about the same people and use
   similar diagrams to illustrate their message. Even the size and price
   of their two books are roughly the same. You could call them two peas
   in a pod - but their flavours are distinct. In short, both are to be
   heartily welcomed as about the best introduction you could hope to get
   to the whys and wherefores of networks, human and non-human.
   John Casti is at the Technical University of Vienna

References

   1. http://www.newscientist.com/opinion/opbooks.jsp?id=ns23539