• by Mark Walsh  @markfwal, September 11, 2009

Nokia today announced acquiring San Francisco-based Plum, a startup focused on powering "micro-sharing" networks for families, co-workers and other groups. The idea behind the company is to let people in small social groups connect through private networks as an alternative to large social properties like Facebook and Twitter.

The move underscores that social networking is increasingly viewed as a key part of the mobile industry's future. At its Nokia World conference last week, the Finnish phone giant announced a partnership with Facebook to offer a "lifecasting" service for the N97, making it easier for people to update Facebook profiles via mobile.

With the unveiling of its social-centric Cliq device yesterday, Motorola is clearly staking its comeback as a phone maker on social media and messaging will play a central role in mobile usage. Other handset makers and wireless carriers such as Verizon and AT&T have launched their own social networking-geared phones and services.

For Nokia, the Plum acquisition could lead to the company developing a "microsocial networking" service on mobile devices, something like a social version of the calling circles offered by the major U.S. wireless carriers.

"This kind of ability to link more intimate and closer-knit groups, like families, is likely what attracted Nokia (NOK), the Finland-based mobile phone giant," noted Kara Swisher in a post today about the deal on her Boomtown blog. It might also complement its lifecasting service with Facebook.

With a company as vast as Nokia, though, it's hard to predict what, if any, impact the acquisition of a 10-person outfit will end up having on its business.