lupka

This plugin allows you to create a widget that will display the title/date/excerpt from random posts in a specified(or open-ended) date range. It can also be used outside of a widget to create custom loops of random posts within a date range. The following can be specified:
<ul>
<li>Number of posts to display</li>
<li>Whether or not to show dates</li>
<li>Whether or not to show excerpts</li>
<li>Excerpt length (number of words)</li>
<li>Start date and End date of posts to randomize</li>
<li>Whether or not to always use current date as end. (Allows you to include new posts without editing settings every day)</li>
<li>Option to use relative time instead (To chose from random posts from last week, year, etc.)</li>
<li>Category to choose posts from. (Example: Random posts from sports category in the past week. This is the original reason I needed a plugin like this. Comes in handy for the newspaper site I run.)</li>
</ul>
Please contact me if you run into any issues, either via email (lupka31@gmail.com) or Twitter (http://twitter.com/lupka) 
For latest FAQs/info visit: http://alexchalupka.com/projects/wordpress/random-posts-widget/

Random Posts Within Date Range Widget

Widget that displays the title(w/ link), date(optional), and excerpt(optional) of random posts within a selected date range.

dyersorg

<a href="http://www.dyers.org/blog/better-blogroll-widget-for-wordpress/#changelog" title="Better Blogroll Change log" rel="nofollow ugc">Changelog</a>
The Better Blogroll widget for WordPress allows you to display a configurable number of random links from your WordPress blogroll. This should help to combat link blindness while still letting you to share the link love with more of your favorite blogs.
Some Features:
<ul>
<li>Links can be sorted randomly, by title, or by rating.</li>
<li>The number of links shown is configurable.</li>
<li>Categories from which links are shown is configurable.</li>
<li>Links can be set to “nofollow” if your links are coming from paid sources.</li>
<li>Capable of Displaying XFN Data.</li>
<li>Displays image links, text links, or both.</li>
<li>Links can be in a single list or separated by category.</li>
<li>Can display each link’s category or rating to its right.</li>
<li>The description of each link appears in a tool tip.</li>
<li>Allows you to show an explanation that the list is a rolling blogroll.</li>
</ul>

Better Blogroll

Allows you to display a configurable number of random links from your Wordpress blogroll

Random Posts Within Date Range Widget vs Better Blogroll