Sami Keijonen

This plugin register a widget to display authors by role in a sidebar. You can choose whether to display author post count, biography or gravatar.
<h4>Usage</h4>
Go to Appearance >> Widgets. There you can find widget called Display Authors Widget. There are some settings in a widget.
<ul>
<li>Title: Set whatever title you want, or leave it blank to disable the title.</li>
<li>Role: Choose which role authors you want to display.</li>
<li>Display Post Count?: This displays the number of posts the author have published. This will only be shown if there are at least one post by author. The format 
is Author name ($number). </li>
<li>Display Author Bio?: If checked, this will display the author’s bio as set in their WordPress profile page.</li>
<li>Display Author Gravatar?: If checked, this will display the author’s gravatar.</li>
<li>Gravatar Size: This is the size of the gravatar image in pixels. Do not write px or pixels in this field. If you want gravatar size to be 50px, then write “50” in this field.</li>
<li>Gravatar Alignment: Choose whether you want to display gravatar on the left, right or no alignment at all.</li>
<li>Limit: This will allow you to set the number of authors that are displayed in the widget.</li>
</ul>

Display Authors Widget

Austin

Activate the plugin then add it to any available sidebar in Appearance→Widgets..
For question please visit my blog @ <a href="http://austin.passy.co/wordpress-plugins/unlimited-lists-widget/" rel="nofollow ugc">http://austin.passy.co</a>
And thanks for rating it! –>

Display Authors Widget vs Unlimited Lists Widget