ALGORITHMS sound scary, of interest only to dome-headed mathematicians. In fact they have become the instruction manuals for a host of routine consumer transactions. Browse for a book on Amazon.com and algorithms generate recommendations for other titles to buy. Buy a copy and they help a logistics firm to decide on the best delivery route. Ring to check your order's progress and more algorithms spring into action to determine the quickest connection to and through a call-centre. From analysing credit-card transactions to deciding how to stack supermarket shelves, algorithms now underpin a large amount of everyday life. Their pervasiveness reflects...