Online social networking services are attracting millions of new users seeking faster "real-time" functionality - in a trend that is leaving established players, such as Google and Microsoft, behind.

Leading social media sites Facebook, which passed 200m active users last week, Twitter and FriendFeed have all begun promoting features that enable instantaneous interaction between users. They are being aided by the increasing capabilities and internet connectivity of mobile devices that allow users to post photos and random thoughts to the web.