You've heard of Wikipedia, no doubt.
What Wikinomics proposes to do is explain how the concept of mass (often, voluntary) collaboration (the wiki principle, as it were) among co-workers, peers, producers, consumers, partners, suppliers, etc. is going to change the way that products and ideas are developed for the marketplace.
And, I have to say, they do a pretty good job of building a case that the paradigm for development is shifting.
Well, they build a good case in terms of facts. The flow/storytelling of the book is a bit redundant and dry, but these guys are consultants, not storytellers (of course, they should be, but that's an argument for a different day).
What I did enjoy about this book is how it continued to expand my mind in terms of what the ongoing Net revolution may mean for industry (and you as consumer) going forward.