Research by the marketing analysts revealed that a third of adults aged between 16 and 35 use their mobile phone to access social networks on a regular basis.
CCS Insight also said that men are twice as likely to access the web using their mobile phone than women. The company also said the BBC's iPlayer is the service most adults would like to see available through their mobile phones.
It is currently only available on a handful of mobile phones, including the Nokia N96.
Paolo Pescatore, head of mobile content at CCS Insight, said: "The web is revolutionising the way people use mobile phones. Forget music downloads and video - social networking is what people want".