Google has just released sidewiki, a toolbar that allows you to attach comments to web pages. This is a step that will allow  a (supposedly) large number of users to attach information to a resource, and Google will try to rank the comments using their ratings, which will be provided by other users. To me, it is an advanced version of  of del.icio.us, which provides a more granular access to other people’s interest in the things you are interested in. If it takes off due to large number of users Google has access to, it may become a very useful tool . It may even have the potential to change the way we do searches on Google, if it allows searching around the chosen page, using comments and commentors’ profiles. This is another case of Google providing a slightly better implementation of an existing idea, leveraging its size. Let’s see what’ll happen.