andeggs

ProSocial is a free WordPress plugin which connects your readers with your authors.
It shows an attractive pop-up bar next to your authors’ names, with links to their social media accounts.
On multi-author blogs, it’s a great way of encouraging your readers to connect with your authors on other social networks.
See it in action here: http://digitalshift.me/prosocial/
Features:
<ul>
<li>40+ social networks: You choose which networks to display. Your authors can add then their accounts themselves.</li>
<li>Includes email: Show your authors’ email addresses as well (with a captcha form to prevent spam).</li>
<li>Google Analytics: If you use Google Analytics, you can see who’s clicking on what.</li>
</ul>

ProSocial

ProSocial shows a pop-up bar next to your authors' names, with links to their social media accounts.

Sam Hotchkiss

This plugin was built by the Maine WordPress Meetup group to make it really easy to add social network icons to your posts.
<h3>This plugin supports the following social networks:</h3>
<ul>
<li>Facebook</li>
<li>Twitter</li>
<li>LinkedIn</li>
<li>StumbleUpon</li>
<li>Delicious</li>
<li>Digg</li>
<li>Reddit</li>
<li>Designfloat</li>
</ul>
You can set this to display at the top or bottom of posts, or display it through a template tag:
<pre><code> socnet_display_links($post_id); 
</code></pre>
Note that the post_id is optional, it will default to the current post.

Simple Socnets

This plugin was built by the Maine WordPress Meetup group to make it really easy to add social network icons to your posts.

ProSocial vs Simple Socnets