Adnan Siddiqi

A sweet and little WordPress plugin that allows you to link any twitter ID along with the URL of the Twitter profile.

Twerrific Lite

A sweet and little Wordpress plugin that allows you to link any twitter ID along with the URL of the Twitter profile.

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.

Twerrific Lite vs WP Social Bookmarking Light