PResponsive

This plugin will add a image below your posts, allowing your visitors to share your posts with their friends, on FaceBook, Pinterest, Google+, Twitter, Myspace, Friendfeed, Technorati, del.icio.us, Digg, Google, StumbleUpon, and other. After plugin is activated a buttons will appear after the content of the post.Clicking this button will bring the user to the bookmarking site. If the user isn’t logged in they will be prompted to do so. 
Post your articles to the social bookmarking sites and get traffic.

WP Social Bookmarking

WP Social Bookmarking plugin syndicates your blog posts in social networking sites.

Ricardo Gonzalez

del.icio.us for WordPress displays your latest del.icio.us bookmarks in your WordPress blog.
Features
<pre><code>* Simply
* Customizable
* Widget ready
* Uses WordPress resources (no extra files needed)
* No options page (yes, it is a feature)
* Displays bookmarks tags (optional)
* Filter bookmarks by tag(s) (optional)
</code></pre>
Usage
If you use WordPress widgets, just drag the widget into your sidebar and configure. 
If widgets are not your thing, use the following code to display your latest bookmarks:
<pre><code><?php delicious_bookmarks("username"); ?>
</code></pre>
For more info (options, customization, etc.) visit <a href="http://rick.jinlabs.com/code/delicious" title="del.icio.us for WordPress" rel="nofollow ugc">the plugin homepage</a>.

del.icio.us for WordPress

del.icio.us for WordPress displays your latest del.icio.us bookmarks in your WordPress blog.

WP Social Bookmarking vs del.icio.us for WordPress