ericabiz

Sorts pages by last modified date in WordPress’s admin panel.

Sort Pages By Date

Sorts pages by last modified date in WordPress's admin panel.

LordPretender

This plugin adds a drop-down list with the ability to sort your blog posts :
<ul>
<li>by title</li>
<li>by date (newest to oldest)</li>
<li>by date (oldest to newest)</li>
<li>sort by date last modified</li>
<li>randomly</li>
</ul>
You can find a demo here : http://www.spoils.fr/ 
The widget is named “Trier les articles” on the sidebar.
<h3>Configuration</h3>
<ul>
<li>Widget title: the title of the widget</li>
<li>3 checkboxes in order to display or not items in the drop-down list.</li>
</ul>
Since the version 2.0.0, it is now possible to change the default order for your categories. 
In the category editing page, you will now find a dropdown list.

Posts Order Widget

Add the ability to sort the posts by context rather than descending date.

Sort Pages By Date vs Posts Order Widget