Bloafer

Use this plugin to apply <a href="https://wordpress.org/extend/plugins/share-rail/screenshots/" rel="ugc">floating shares</a> to your posts and pages.
This is very similar to the one found on mashable.com.

Share Rail

Use this plugin to apply floating shares to your posts and pages.

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.

Share Rail vs Simple Socnets