Pigi

Using this small plugin you’ll be able to deliver content Around the web.
You can choose what Social Network website include in your post; what layout use to this plugin between:
<ul>
<li>Horizontal (default)</li>
<li>Vertical</li>
</ul>
Supported Website:
<ul>
<li>Facebook</li>
<li>Twitter</li>
<li>Friendfeed</li>
<li>StumbleUpon</li>
<li>Feed RSS DELIVERY</li>
<li>Digg</li>
<li>Google Buzz</li>
<li>Yahoo Buzz</li>
</ul>

Social Network Sharer

Using this small plugin you'll be able to deliver content Around the web.

Anthony Hayes

Syndicate you wordpress posts to facebook, twitter, plurk, tumbr, friendfeed, livejournal, Post your wordpress posts to facebook, twitter, plurk, tumbr, friendfeed, livejournal, diigo, delicious and linkedin.
Share and reshare the posts 
Reblog the posts, tweet and retweet the posts

Social Traffic Commando

Reblog, reshare, retweet your wordpress posts to facebook, twitter, plurk, tumbr, friendfeed, livejournal, diigo, delicious and linkedin.

Social Network Sharer vs Social Traffic Commando