It's quite annoying to find out that groups make better decisions than you can as an individual - but a very powerful thought. However, the groups need to be diverse, independent and decentralised (so that may exclude a few crowds I can think of...)
We are essentially cooperative beings and meld our behaviour around that of others. One of the examples in the book is how crowds flow in shopping centres, how we move on staircases etc. We do all this even when there are no explicit rules. Mind you, as someone who regularly travels to the US from the UK I know what it is like to accidently move against this flow when I forget to walk on the "right". So maybe there are more socialised rules and logic than the author makes explicit.
One theme in the book which did appeal to me was the notion of the difference making a difference. While it seems inefficient, having a diversity of ideas seems to allow meaningful differences of ideas, especially at the early stages of decision making - and this is important. Groups also need to be able to distinguish good ideas from bad ideas and having more to choose from helps.
There is some helpful work about distinguishing the difference between situations which are easily defined by a single answer, such as the weight of an ox, and those which are more co-ordination problems, such as traffic manageemnt. Co-ordination problems come when all individuals want to go their own way. Here the wisdom of the crowd sound a lot like complexity science and simple rules and I wasn't totally convinced of all of his arguments. However, they were interesting.
A thought provoking book which much more to say that the few bits I have mentioned here.
The book's website is here http://www.randomhouse.com/features/wisdomofcrowds/ where there is a lot of detail and audio to download.
