The web is being reinvented, and this time it is people - or, more precisely, the personal information and social connections they enter into social networks - who are at the centre.

That view has taken hold in Silicon Valley with in-creasing force this year. Last month it prompted Microsoft to make an investment in Facebook that valued the upstart website at $15bn. And it has led Google to come up with a strategy to try to counter a potential shift in the way the web is organised that could hamper its own long-term position.