Example Timeline (of Scobleizer) - http://beta.memolane.com/scobleizer
It has not yet opened to the public, but I've got hold of 500 Invites, so you can get the invite code by visiting the blog
I was a little skeptical about the idea, but when I saw my own timeline after they pulled information from my social accounts, I must say that I was impressed. Actually seeing your timeline laid out in an easily accessible manner is a powerful (and more than a little nostalgic) experience.
One thing though is that they put the same emphasis to all my posts/tweets/facebook events etc. And there is a lot of 'junk' in my timeline. I wish they had some way of figuring out what is important to me and have display emphasis on the important nodes (mirror the way I think). Pretty neat in it's current beta stage nonetheless.
But I'm sure the memolane team will come up with a solution soon :)