This Is Your Life (According to Your New Timeline)

At Facebook's F8 developers Conference in San Francisco last September, CEO Mark Zuckerberg introduced the site's new page motif, Timeline. F8 has played host to most of Facebook's biggest announcements--new profiles, the Like button for websites, Graph API--but this one had the usually unflappable Zuckerberg looking a little giddy. "We're more than just what we've done recently," he told his listeners, and he laughed as he scrolled through his own Timeline to show the audience a few of his baby photos.

Timeline, which is being introduced to all Facebook users over the next few weeks, is a complete rewiring of the...