This plugin provides an easy framework to add Digg buttons and Digg widgets to your page. Digg buttons help drive traffic to your content by allowing easy Digging and submission into the Digg ecosystem. Digg widgets allow you to supplement your content with the top stories from Digg either through the lens of your site or through a specific area or topic from Digg.
Out of the box, it allows you to:
<ul>
<li>Place yellow smart Digg buttons in the three size options: compact, medium and large. The yellow smart Digg buttons can tell if a web page has been Dugg or not and displays the proper number count. </li>
<li>Generate a customized Digg widget with different placement options. The widget generator can show the most Dugg content by domain, topic, search term or even show a particular user’s Dugg stories. After selecting the type of content to display, it’s easy to save that state and decide where to position it on a page.</li>
</ul>
The Digg plugin is developed and maintained by Digg Inc. and will be updated regularly as new capabilities are introduced to the Digg platform.

Digg

The Digg plugin provides an easy framework to add Digg buttons and Digg widgets to your page.

Scott Grayban

It puts a bar of icons at the bottom of each post allowing your readers to submit your posts to several different 
social networking and bookmarking sites. (del.icio.us, digg, fark, etc.)
The original plugin was called <a href="http://blog.calevans.com/2006/02/08/notable-another-wordpress-plugin/" rel="nofollow ugc">wp-notable</a> 
but no longer worked or was supported. The author was Cal Evans.

notable

Adds social bookmark links to each blog entry.

Digg vs notable