Sidewiki is a new addition to the Google Toolbar that will let users read comments on any Web site and add their own in a special interface on the left hand side of the screen enabled by the toolbar. This idea has been tried before by others, but Google is proposing to use an algorithm to rank comments by quality and to link comments to a user's Google Profile.
Google has developed an algorithm that it says can filter out obvious spam, naughty words, and the classic all-caps technique employed by some of the Internet's more unhinged pundits, said Caesar Sengupta, group product manager at Google. As comments build over time, a recursive algorithm can analyze the quality of past comments using reader votes on the comment's usefulness.You can share your comments with your Facebook or Twitter accounts, and can post a link to a blog item discussing that Web page with a snippet of the text, Sengupta said. Only Google Toolbar users will be able to see the comments on the Web page, obviously, but Google plans to work on an API (application programming interface) that will allow developers to use Sidewiki in other places.