By Edwin Black Jay Leno probably said it best a few weeks ago when he joked that when Wikipedia's servers briefly went down for some three hours, it left the world without a source for false and erroneous information. But many in our information-driven society believe it is no joke. A growing community of the informed believes that Wikipedia, the constantly-changing knowledge base created by a global free-for-all of anonymous users, now stands as the leading force for the dumbing down of world knowledge. If Wikipedia's almost unstoppable momentum continues, critics say, it threatens to...