Google Notebook was launched in 2006. It was announced at the second annual Google Press Day on May 10th, 2006. The Notebook is a tool for saving "clippings" of websites. It ran in the user's browser. Like Google Calendar, users have the option of sharing the content of the Notebook with other users.
In 2011, Google discontinued the service in favor of the more advanced Google Docs service. A blog post on why they discontinued it can be found on the Google Notebook Blog. It is still available to use for people who used it before it was discontinued.
Data migration started November 11, 2011; but as of July 23, 2012, however, Google Notebock is still running.