H. Peter Pfeufer

Twitter has provided a twitter and retweet button. This Plugin adds the official twitter button to your blog articles, pages, archives, categories and rss.
Features
<ul>
<li>Easy install</li>
<li>Panel for easy configuration</li>
<li>Config Button Style</li>
<li>Config Language of Button</li>
<li>Config Your Twitter Account</li>
<li>Config Tweet text</li>
<li>Config display locations (entries, pages, home page, archive, category)</li>
<li>Config position in content (before, after, both, manual choice)</li>
</ul>
Note
If you choose the position as “manual choice” you have to edit your template-file and add the following code at a position of your choice. 
 <?php if(function_exists(‘wp_twitterbutton’)) { wp_twitterbutton(); } ?>
Translations
<ul>
<li>English</li>
<li>German</li>
<li>French (by: <a href="http://www.frankoli.de/blog/" rel="nofollow ugc">Frank</a>)</li>
<li>Dutch (by: <a href="http://wpwebshop.com/" rel="nofollow ugc">Rene</a>)</li>
<li>Czech (by: <a href="http://blog.michalbernat.cz/" rel="nofollow ugc">Michal Bernat</a>)</li>
<li>Hebrew (by: <a href="http://www.sagive.co.il/" rel="nofollow ugc">Sagive</a>)</li>
<li>Hindi (by: <a href="http://outshinesolutions.com/" rel="nofollow ugc">Love Chandel</a>)</li>
</ul>

WP-Twitter Retweet Button

This plugin will install the official Twitter Button provided by Twitter to your Wordpress-Blog.

svil4ok

Twitter Button is a WordPress plugin that allows you to easily integrate <a href="http://twitter.com/goodies/tweetbutton" rel="nofollow ugc">Tweet Button</a> in your blog.
Features
<ul>
<li>Easy customization.</li>
<li>Three methods to include Twitter Button in your blog – automatic, manual or by shortcode.</li>
<li>Exclude Twitter Button from certain pages (admin option).</li>
<li>Styling option for the div element that surrounds the button.</li>
<li>Twitter Button can be placed in different positions in the post – top, bottom or both.</li>
<li>Admin panel language support</li>
<li>Restore option</li>
</ul>
Translations
<ul>
<li>Bulgarian (bg) by <a href="http://www.svil4ok.com/" rel="nofollow ugc">Svilen Popov</a></li>
<li>English (en) </li>
<li>French (fr) by <a href="http://wpchannel.com/" rel="nofollow ugc">Aurelien Denis</a></li>
<li>Italian (it) by <a href="http://www.blog.webgenerate.net/" rel="nofollow ugc">Webgenerate</a></li>
<li>German (de) by <a href="http://dopanic.de.vu/" rel="nofollow ugc">Christian Schulz</a></li>
<li>Macedonian (mk) by <a href="http://wp.mk/" rel="nofollow ugc">Boris Kuzmanov</a></li>
<li>Romanian (ro) by <a href="http://byubay.nodomain.ro/" rel="nofollow ugc">Byubay</a></li>
<li>Spanish (es) by <a href="http://blog.josemi.net/" rel="nofollow ugc">Josemi</a></li>
<li>Croation (hr) by <a href="http://www.mojportal.com.hr/" rel="nofollow ugc">Roberto Bilic</a></li>
</ul>
If you have created your own language pack, or have an update of an existing one, you can <a href="http://www.svil4ok.com/contact" rel="nofollow ugc">send it to me</a>. If you want to translate the plugin in your language, but you don’t know how, <a href="http://www.svil4ok.com/contact" rel="nofollow ugc">contact me</a>, I’ll help you out.
<a href="http://www.svil4ok.com/wordpress-plugins/twitter-button/#installation" rel="nofollow ugc">More information</a> | <a href="http://www.svil4ok.com/wordpress-plugins/twitter-button/" rel="nofollow ugc">Demo</a> | <a href="http://www.svil4ok.com/wordpress-plugins/twitter-button/#screenshots" rel="nofollow ugc">Screenshots</a>

Twitter Button

Twitter Button is a WordPress plugin that allows you to easily integrate Tweet Button in your blog.

WP-Twitter Retweet Button vs Twitter Button