Robin Good: Timekiwi is a free web app that alows you to automatically create a cool-looking timeline of your social activity across the networks you choose (Twitter, Facebook, Flickr, Tumblr, Foursquare, Instagram, Overblog - but more are being added).
In horizontal view (click Rotate on the bottom left) the timelies are really great and easy to navigate thanks to Calendar-menu in the bottom right.
You can further curate the look of your timewiki in the Customize menu and select which items to "show" and which ones to "hide" by clicking on the appropriate button next to each story.
A "company" version, costing $5/mo provides more control over curation and the option of embedding the timeline in any web site.
N.B.: You need to give some time to timewiki to collect all your past social activities.
Try it out now: http://timekiwi.com/