WereWP

Themes and Plugins For Extreme WordPress Functionality | W3Avenue
Here is a list of themes and plugins which either change the overall function of your website from a blog to something else or add new function that will otherwise require a separate software.

Widgets in WordPress 2.8
I have presented you a very complete tutorial about widgets a few weeks ago, but here are a few others to help you manage your widgets easily:

Creating Widgets in Wordpress 2.8 with the Widget API | WooCamp
A tutorial from Woothemes team, to teach you how to create your own WordPress widgets.

Kaspars Adds Widget Context [...]