Brian Zeligson

It seems like every twitter plugin for WP does one of two things- pushes your blog posts to twitter, or shows your own tweets on your site.
I wanted to show tweets of the people I follow on my sidebar, and it seemed like it hadn’t been covered yet. Fortunately I knew of an awesome jQuery plugin, Seaofclouds Tweet! – http://tweet.seaofclouds.com/- 
that lets you not only show tweets from a twitter list, but also from a search query, and of course just from a specific user. You can customize appearance with CSS and custom templates that control the content 
that appears in the tweets.
A quick port to WP and you now can have all this flexibility from the Settings->Tweet! menu in your WP Admin. Add tweet feeds from the settings page and then add them to your site using the widget or shortcode.
Details on shortcode and custom template use are found on the settings page.
Check out http://www.workinginboxershorts.com for more plugins, support, or to contribute code.

Seaofclouds Tweet!

Super flexible Twitter plugin for displaying tweets on your blog

utahta

This plugin inserts social share links at the top or bottom of each post. 
For theme developers, social share links can be added by PHP code or by using shortcode. Check documentation for this use-case.
This plugin documentation can be found <a href="https://github.com/utahta/WP-Social-Bookmarking-Light/wiki" rel="nofollow ugc">here</a>.
This is the list of used social sites:
<ul>
<li>Hatena</li>
<li>Facebook Like Button</li>
<li>Facebook Share Button</li>
<li>Facebook Send Button</li>
<li>Twitter</li>
<li>Tumblr</li>
<li>Google Bookmark</li>
<li>Google +1</li>
<li>Delicious</li>
<li>Digg</li>
<li>reddit</li>
<li>LinkedIn</li>
<li>Instapaper</li>
<li>StumbleUpon</li>
<li>mixi Check</li>
<li>mixi Like</li>
<li>GREE Social Feedback</li>
<li>atode (toread)</li>
<li>LINE</li>
<li>Pocket</li>
<li>Pinterest</li>
</ul>

WP Social Bookmarking Light

This plugin inserts social share links at the top or bottom of each post.

Seaofclouds Tweet! vs WP Social Bookmarking Light