MartinLogan

For Your Readers 
Empower your readers with a social tool for sharing, saving and discovering new content with the click of a button. Our plugin provides social features for sharing content across all major social bookmarking sites and a clipping feature for adding text, images and personalized messages for friends, family and co-workers.
For Publishers 
Download our free content monetization plugin by adding your Google Adsense ID, embedding ads into shared content and keeping all revenue generated by the viral effect of people discussing your articles and blog posts. That’s right, 100% of ad revenue is yours.
The Share+ button offers the following features for readers and publishers:
<ul>
<li>Automatic Plugin Updates</li>
<li>Email This (with private discussions and forum) </li>
<li>Content Clipping (add photos and personalized messages)</li>
<li>Social Bookmarking (all major services and browsers)</li>
<li>Portable Address Book (access all contacts anywhere on the web)</li>
<li>Tracking and dashboard for your blog or website</li>
</ul>
The days of cutting and pasting links are over. With the Share+ button by Grouptivity, your readers get a better experience and tools to track the articles, posts and clips they share with friends. Web publishers get access to a free Content Monetization Platform that allows them to drive 3 times more traffic and make money from the viral spread of their content. Make your content work for you and get started today!

Share+ by Grouptivity

Not just another sharing plugin. Share+ gives readers a simple way to save, share and discover your top content with friends, family and co-workers.

goldenapples

This plugin aims to support community link-sharing, social bookmarking, and discussion of links in the WordPress environment.
This is still at an early stage of what I hope will be a much more ambitious project. If you want to try this out, please give me feedback.
I will guarantee backwards compatibility with all data saved by the plugin, so it should be safe to install and activate, and as I add features, your existing posts and links will work with them just fine.
See the plugin’s <a href="https://github.com/goldenapples/recommended-links/wiki" rel="nofollow ugc">wiki page on github</a> for more up-to-date documentation (its hard to keep documentation updated in multiple places).

Share+ by Grouptivity vs Recommended Links for WordPress