Obama to be 1st head of state to tour Facebook HQ

When President Barack Obama arrives at Facebook headquarters this week, he will be the first sitting head of state to visit the brick-and-mortar home of the social media powerhouse.

He will also be partaking in a unique pilgrimage to the Northern California tech hub, known as Silicon Valley, that has become a cradle for social media, a trip that is all but obligatory for politicians like presidential hopefuls, celebrities like Lady Gaga and dignitaries from around the world like Russian president Dmitry Medvedev. (AP)