Wikis demonstrate the possibility of aggregating small information chunks from many contributors into meaningful knowledge aggregates. Other Web 2.0 technologies, from tag clouds to social search engines, provide further evidence for this growing opportunity. Using wikis and related technologies, significant insights can be drawn from many small chunks of knowledge that carry relatively little meaning individually, but become exceedingly meaningful when combined. The tutorial will demonstrate how wikis, as well as newer Web 2.0 technologies, can be used to generate insights from aggregating many small contributions. Through several examples, both conceptual and hands-on, we will explore the mechanisms of knowledge aggregation in theory and practice. Upon completion of the tutorial, participants are expected to better understand the principles of collective intelligence (often referred to as the Wisdom of Crowds) and how to put the principles into action in their environment with wikis and other Web 2.0 technologies.