Google has just updated their dashboard post in the forum detailing the new Places for Business Dashboard with the following one button upgrade of your listing to the fully social G+ page:
What does the Google+ widget do?
The Google+ widget allows you to upgrade from a Google business listing to a local Google+ page (with social features, like writing Posts, editing the cover photo, allowing users to add the page to their Circles, and adding videos). The upgraded page will be searchable in Google, Google Maps, and Google+.
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