Nokia's acquisition of Plum Ventures assets is another milestone in the move on the part of mobile phone vendors to pick up social-network technology as they hunt for new ways to get consumers to buy handsets.

Social networking is where it's at in the mobile application market, according to Paolo Pescatore, analyst at CCS Insight.

For example, the Nokia acquisition, announced Friday, was followed Monday by LG's announcement of its first Android phone, which will support social networking out-of-the-box. Social networking will also play a key role on Motorola's recently announced Android based mobile phone Cliq.

Users want access to Facebook on their phones, Pescatore said. On Sep. 3 Facebook announced it had reached a milestone with more than 65 million people actively using Facebook on their mobile devices -- a significant increase from 20 million just eight months ago.

A large part of the social networking push is about making the big networks as easy as possible to use on mobile phones but with the technology from Plum Ventures, Nokia most likely has something else in mind. Plum will become a part of its services unit, complementing its social location services, which link social contacts to users' physical location, according to Nokia.

Nokia and Plum did not provide further details, however. Nokia said it would acquire "certain assets" of Plum but did not specify those assets.

Plum's social networks consist of so-called Plum Groups. Plum Groups is a service for those who want to share the more private parts of their lives with small groups of people they are close to, according to a blog post by Hans Peter Brøndmo, Plum's CEO and co-founder. It fills the need for "private" sharing and conversations, he wrote.

The company has also developed the Social Groups Platform, which is designed to host and operate public and private social networks for groups.

Nokia will likely use Plum's technology to build a new mass-market service, Pescatore expects. Sharing location information with a large group is not something everyone wants to do, but keeping location information limited to only a smaller group of family and friends could make sense for many users, Pescatore said.