Classy wp_list_pages adds classes to the LI tags generated by WordPress f wp_list_pages() function.
Cleaner Dashboard removes WordPress News and Other WordPress News from your dashboard and makes the dashboard sidebar more horizontal, with four columns instead of the default one.
Tags4Page allows you to insert tags on pages.
Who’s Linking Me? shows backlinks to your blog from Technorati.
WordPress Upgrade Preflight Check attempts to check your other plugins and themes for problems that may cause errors when upgrading to WordPress 2.3.
WordShout creates a live shoutbox, using AJAX as a backend.
I have made a spanish translation of the Upgrade Preflight Check plugin for even better help for people that speak spanish 😉
Upgrade Pre-flight Check is a must-have prior to upgrading to 2.3.