Facebook users worldwide will have their user profiles replaced by an "an entirely new kind of profile" shortly, the social networking service has announced.

Facebook Timeline, designed to be an online scrapbook that emphasizes "important life events" throughout users' lives, filed by year, launched worldwide Thursday, Facebook announced on its blog. The company had first unveiled the tool at a news conference in September.

Users will have the option of switching to timeline immediately, but they can also opt to stay with their current profiles, which mainly showcase a user's most recent activity on Facebook, for now. Facebook has not indicated when timeline will completely replace existing profiles.

Once users have activated the timeline feature, the social networking site is giving people seven days to review everything that appears on their new timeline profiles before they automatically become visible to other people. Users can also choose to make their timeline public earlier if they like.

But before they do so, Facebook recommends:

  • Featuring important stories and removing or hiding others.
  • Using the privacy dropdown to adjust who can see any of your posts. It's possible to make some visible only to yourself.

Facebook noted that users also have access to a new feature called "activity log," invisible to others, that allows them to review everything they have ever done on Facebook since they joined, and also to adjust the privacy settings and prominence of each post.

Alexandre Lainesse, an account executive at High Road Communications, which represents Facebook, said in an email that the new timeline is a "powerful tool to document your life."

He added that users may also want to fill the timeline out "with special moments in your life" that aren't already on Facebook, such as baby photos, graduations, engagements or weddings and add a "vivid cover page that represents you."

Facebook has 18 million active users monthly in Canada.