Amie

This widget replaces the standard Blogroll widget, and adds the following features:
<ul>
<li>API compatibility, so the widget matches the theme</li>
<li>Respects options set in the Links Manager Admin Panel</li>
</ul>

WPW-Linkslist

A flexible replacement for the standard links widget, for wordpress 2.0.x only.

JohnnyPea

Simple widget based on the default Links widget. It displays random links on your website.
I am open to suggestions to improve the plugin !

Rotating Links Widget

This plugin add widget which displays random links on your website.

WPW-Linkslist vs Rotating Links Widget