Just when you thought Facebook couldn't get any more distracting, here comes Timeline.

The Menlo Park, Calif., firm means this new profile format–now rolling out on the web and in most of Facebook's mobile apps to its 800-million-plus users–to be your digital autobiogaphy. After a week with Timeline, the scary thing is how well it does that, combining the time-suck distraction of an old photo album with the added lure of instant feedback.

NEWS: Facebook Flaw Means Anyone Can See Private Photos

When you get this feature, it's easy to get lost in your own history. In my case, I was retroactively embarrassed to see how many months I waited to start using my account after opening it in January of 2006. Then I was amused by how the volume of my birthday greetings tracked Facebook's growth: one in 2006, nine in 2007, 32 in 2008, 47 in 2009, 82 in 2010 and 117 this year.

(Whether all those people would have remembered the date without Facebook's help is an excellent question.)

But set aside navel-gazing to curate your Timeline during the seven-day preview Facebook allows before making it visible to others.

You can start by picking a "cover photo"–a banner image, like the ones that adorn many blogs, to run atop your Timeline. Among the 152 friends that have Timeline so far, outdoor photos seem popular; mine was a telephoto shot of the Potomac River, National Airport and five bridges.

Next comes a gentle scrubbing of your Facebook history. This three-step procedure begins with the "Highlights" that Facebook automatically picks, which I found overemphasized posts from friends in which I'd been tagged. You can't demote these items from Highlights, but you can hide them from Timeline or delete them altogether. You can also change their date, add a location and adjust their visibility. (I'd forgotten that for a year or so, I left my updates visible to "Friends and Networks," not friends only; that's fixed now.)

If you plan to apply for a job or run for office, you should also inspect the "All Stories" view of prior years–a painfully slow process. For the most complete look, the "Activity Log" option shows everything you've done on Facebook, including comments on other people's profiles. Tip: Watch out for after-midnight input, especially on holidays.

The most fascinating and risky feature of Timeline is Life Events–key points of your personal, even pre-Facebook history. The suggested choices cover everything from "New Language" to "Loss of a Loved One" to "Tattoo or Piercing." I'd stick with big moments–say, marriage, birth of a child, running a marathon, seeing a space shuttle launch–but one friend has used this feature to testify to having his wisdom teeth yanked.

I can admit that it's gratifying to get compliments on your achievements years after the fact. But beware that by default, Life Events are public. And although you can make individual milestones visible only to friends, you can't make that your standard for future Life Events.

ANALYSIS: Don't Blame Facebook

Your Timeline goes all the way back to your own birth. Fun fact: Although some of the six current and former Facebook employees on my friends list have added baby pictures, none have added the year of their birth.

The trickiest part of Timeline is still unfolding: the new crop of optional apps, touted at Facebook's unveiling of Timeline in September, that broadcast your activity at another site or service in real time. It may be fun to share your Spotify playlists or news stories you've read with friends, but do you want that to go on your permanent record?

Credit: Rob Pegoraro/Discovery