Ubiquity of the social graph

Networks - professional or otherwise that started off as fads have the possibility of evolving into very potent tools for the internet and it's users. The metamorphosis that some of the networking sites have gone through could not have been planned (people might claim so !).
If you ask me, the idea of social / professional networks must have originated from the old Web 1.0 (if you please) concepts of discussion boards, mailing lists and communities .. sounds more like an evolution path to me.
Well then, what next ? Shall address that in a bit, right now let's understand the current situation : there are plenty of social networking sites right now being used extensively / sparingly depending on the country you are in.Which is a problem, because if as a user you have to expand / cross-pollinate your networks amongst these various sites, you can not do so unless you register with all of them or ask people you'd like to network with, to move in on one of these sites that you are at. Any which way, you would have to maintain different networks across different sites and these networks exist in a Euclidian paradigm.
So, the solution is simple, have an unique identity for each user that all these sites recognize.Well, it actually is not as simple as it sounds.Although Facebook opening up it's network through apps and MySpace vowing to follow suite, the networks may be accessed but they would remain to be locked-in aat these individual sites.
And as a user, I don't like that.
I'd love for my graph to be ubiquitous,accessible and extensible with ease, independent of the platform (read a specific site).