Wikipedia founder Jimmy Wales spoke about his "radical encyclopedia" at Yale Law School a few weeks back, and he shared the company's mission statement: "Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge."  A noble statement, and there is no doubt that Wikipedia has utilized digital technology to break down a lot of barriers to knowledge.  But the "free access" piece of the statement is particularly eye-catching.  In his talk, Wales shares some data on Wikipedia's global rise as an interactive information source, and some of the numbers are impressive.  But the central piece of this talk is about Wikia and Wikipedia as examples of the power of free and participatory culture.