andreyk

The WP Ya.Share plugin adds to your blog a set of buttons to save URLs of your pages/posts in popular social networks (twitter, facebook, livejournal, vkontakte etc.).
Добавляет блок ‘Поделиться’ (Ya.Share, разработанный в yandex) для сохранения ссылки просматриваемой страницы вашего блога в популярных ‘социальных сервисах’ (вконтакте, жж, твиттер и т. д.).
It uses the Yandex Ya.share API; I shaped it into wordpress plugin with some options only.
The following options are available:
<ul>
<li>locate “ya.share” block either in the content of a page/single post or in the sidebar (as a new widget);</li>
<li>select a list of preferable social networks;</li>
<li>button/link/icon for expanded social networks list, or nothing;</li>
<li>left, right or centered location;</li>
<li>above or under the content;</li>
<li>inscription language. 
Please feel free to contact me with your questions or suggestions.</li>
</ul>

WP Ya Share

Adds the Yandex 'Share in social networks' block into posts or widget to simplify saving URLs of your blog pages into social networks.

svil4ok

Adds a list of XHTML compliant graphic links at the end of your posts that allow your visitors to easily submit them to a number of social bookmarking sites.
Social sites:
<pre><code>* Svejo
* Favit
* Facebook
* Twitter
* Edno23
* Dao
* Delicious
* Google Buzz
* Google Bookmarks
* Digg
</code></pre>
<a href="http://dev.svil4ok.info/wordpress/add-to-social/" rel="nofollow ugc">Demo</a> | <a href="http://dev.svil4ok.info/wordpress/add-to-social/" rel="nofollow ugc">Plugin information</a>

WP Ya Share vs Add To Social