Facebook will also be integrated into iOS 5

Just like Twitter, the most popular social network of the moment - Facebook - will arrive with a smart integration within Apple's mobile operating system, iOS 5, which is expected to be released on October 4th.

An image from MacRumors suggests that Facebook will be deeply integrated into the operating system, with push notifications, rather than being just another app. This appears to be one of the major announcements when iOS 5 is unveiled.

The social network boasts over 800 million users and is one of the most popular activities for smartphone users: interacting with your contacts from the palm of your hand.