Sutherland Boswell

Import your latest Google+ activity into your site as posts. Currently supports most types of activity on Google+ with more options coming soon.
This is an early version so use wisely. Please let me know about any bugs or requests.
<h3>Roadmap</h3>
This plugin is currently in its early stages, so send your feedback or ideas to sutherland.boswell@gmail.com and I’ll keep them in mind as development continues. Look for frequent updates, new features, and bugfixes.

Google+ Importer

Automatically create new WordPress posts from your activity on Google+ using Google+ Importer

Mervin Praison

This plugin helps you add Google authorship markup to your WordPress site, allowing your Google Plus profile picture to appear in Google Search results.
Features: 
* Easy 4-step setup process 
* Multiple author support 
* Multisite compatible 
* Shortcode support

WP Google Authorship

Nice

Google Plus Profile Picture appear in Google Search. Very Easy to implement. Including Google authorship for multiple authors and multisite.

Google+ Importer vs WP Google Authorship