Dandelife is a social network with a special design : It is made to record and share your life's biography. By doing so you actually record the timeline of your life, as far or deep as you like. By tagging you can get to other person's timelines that share tags with you. That's where the network is built.
One very important feature is the integration of Youtube videos and images from Flickr, making this a powerfull and rich Social Network. The only trouble I foresee is a big pile of logins, websites and passwords to remember, although more and more services are combining the power of several others so you can minimize the amount of information you have to remember.