New figures show that almost 82 million people in the US, or 26 percent of the nation’s population, are now accessing social networks from their mobile phones. But if you happen to be thinking this could be a golden opportunity for your own social networking startup, think again – Facebook has the market all but wrapped up, accounting for 85% of all social mobile traffic.

The report comes from eMarkter, who based their estimates on a wide range of traffic and survey data from regulatory agencies and research firms, as well as company-specific data, historical trends, socioeconomic and demographic factors.

But while these stats might make it look as if mobile growth is positively booming, in fact it seems that the opposite is true. Although the number of social mobile users in the US is set to grow to 117 million people by 2014, this represents an increase of just 18%, compared to 50% seen in 2011. No doubt by 2014, when almost half the US population will be social mobile networkers, pretty much everybody who wants to get ‘socially connected’ on the go will have already done so by then.

There are two things we can draw from this data; first, it seems that for the foreseeable future at least, PCs are going to remain the most popular way for people to connect with social networks, and so this will likely retain the highest priority from Facebook and co.

Second point, it seems as if the ‘landgrab’ for social mobile may finally be tailing off as growth slows down, although social sites such as Pinterest that follow a new concept may very well have a thing or two to say about that.