In a move widely seen as the Silicon Valley behemoth's answer to Wikipedia, this week Google opened Knol, its own user-generated encyclopedia, to the public. Unlike Wikipedia, people who write entries on Google's encyclopedia are identified and could even earn a profit from their articles with ads. The more times the article is viewed, the more an author can get paid. Google, of course, gets a cut of the profits. "The key principle behind Knol is authorship. Every knol will have an author (or group of authors) who put their name behind their content," the company wrote on its blog...