The upshot: On a global basis, it will be extremely challenging to move 5+ billion people from telephone number based ecosystem to one that registers some, other addressing scheme to reach people, businesses or enterprises without multiple 'social' or 'enterprise' communities. Of course, the biggest community of all is the global PSTN (Public Switched Telephone Network), based on the ITUs E.164 standard, which defines the international public telecommunications numbering plan or the format of telephone numbers around the world.

We'll probably always have to map telephone numbers, e-mail addresses, IM handles, and other addresses to our friends and enterprises, through various clients or apps. People will need to be smart about it, as everyone will have different preferences as to how they will want to be contacted. It all began with the simple, automated contact list. Now, Facebook has taken this to a new level, by integrating various forms of 'messaging channels' into a intelligent, universal client or as they call it the Social Inbox. I think this is a great start and one that will evolve across a variety of 'communities' and not just Facebook. Time will tell.

in Network World's LANs & Routers section.