The book: MacroWikinomics: Rebooting Business and the World, by Don Tapscott and Anthony D. Williams; Portfolio.

The big idea: None of us are as smart as all of us. MacroWikinomics describes a new world in which innovation and problem solving are accomplished through collaborative networks.

The backstory: Tapscott heads nGenera Insight, a think tank, and teaches at the University of Toronto's Rotman School of Management. Williams is a senior fellow at The Lisbon Council, also a think tank. Some critics griped that Wikinomics -- the pair's 2006 book, which laid out the economics of mass collaboration -- was too optimistic. The authors are still breathless, but this time it's thanks to their many real-world examples.

If you read nothing else: The chapter on reinventing financial services, which proposes casting a public eye on risk management and the valuation of financial products, is timely. The education chapter's vision of a "meta-university," at which students learn from the best professors anywhere in the world, is inspirational.

Envelope pushers: Mixed in with the usual suspects -- Zipcar, the Huffington Post -- are many cool examples like Local Motors, a start-up that leverages an online community of 4,500 designers to create next-generation cars.

Rigor rating: 8 (1=Who Moved My Cheese?; 10=Good to Great). The authors used principles of mass collaboration to solicit ideas and examples, resulting in hundreds of named contributors.