This book is about how groups that are diverse, decentralized, make decisions independently, and have some method of aggregating individual decisions, will very often consistently make better decisions than any one member of the group.

The classic example is asking a group to guess the number of jellybeans in a jar--the group's average guess will consistently be better than any one group member's guess.

Surowiecki, who writes for the The New Yorker, takes this model and applies it to areas like financial and decision markets, business strategy, and traffic patterns to show how group decisions are often better than an expert's. A fascinating and easy read--read it if you enjoyed The Tipping Point or anything by Michael Lewis.