The Wiki module
A wiki is an area of the website where visitors themselves can edit the content or create new content. One of the most famous wiki's on the web is Wikipedia (http://www.wikipedia.org/) — an online encyclopedia that anyone can contribute content to.
Another example wiki is the ExpressionEngine wiki, located at http://expressionengine.com/wiki/ — a great tool for sharing how-tos and more with other ExpressionEngine users.
At first glance, it can be difficult to see the use for a wiki (especially for a website like Ed & Eg's). However, if you think of it as a collection of documents that can be shared among a group of people of any size, and updated in real time by the same group of people that actually use the content, the business ...