Every time you modify a post slug, add a new post, rename a category, or otherwise modify any of your post and page permalinks, jadedcoder Sticky Permalinks (jcsp) will keep a copy of the original permalink along with the post or page it originally led to. If anyone tries to access the old URL, they will be redirected right to the new one, no matter how many times you’ve changed it.
If you re-use a URL that has already been used in the past, its copy will be replaced and it will safely link to the new article instead.
Don’t throw away valuable URLs! This plugin lets you re-organize your site as many times as you want, without risking traffic loss.

jadedcoder Sticky Permalinks

Keeps a history of your permalinks no matter what changes you make on your site, and redirects old links to the new ones.

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.

jadedcoder Sticky Permalinks vs Simple Socnets