ZbigniewLukasiak has a generalized version of TheFlowInternet called SocialRouting. He's thinking of P2P SocialNetworkingSoftware which can automatically route and filter messages.
Wiki : http://zby.aster.net.pl/kwiki/index.cgi?SocialRouting
Another vision : http://www.webdesignfromscratch.com/future-social-web-experience.cfm
JonUdell on pub-sub, tags and human filters : http://weblog.infoworld.com/udell/2004/08/13.html
See also his stuff on ReconnectingTheSmallPieces and FolkSonomy
RossMayfield and JohnBattelle try to use it to diseminate adverts : SellSideAdvertising
And (WarpLink) BloggingPersonalizes for more on branding and SocialNetworks