It is amazing how exciting Social Networking is!!! I stumbled upon this service today!!!
I see the Vannebar Bush dream unfolding very rapidly. Many people are in this innovative race against the giants. So to make a short list of these socialistic networking infrastructure providers:

* del.icio.us (*****)
* linkedin (?)
* tagworld (?)
* myspace (?)
* stumbleupon (*****)
* google notebook (*****)

The problem now is that I expect to be able to tag anything on my computer. I am working on a thesis and while I research I need to tag things like I do with little PostIt notes in my books, but I cannot tag in the same way with PDF and Word documents. There must be a fully integrated tagging environment that is transparent. At lease desktop search tools help a hell of a lot to break that barrier between my space and the Internet.