Widget Logic
By Alan Trewartha (http://freakytrigger.co.uk/author/alan/)
Why it's awesome: Target widgets to specific parts of your blog
Why it was picked: Support for all WordPress conditional tags
Manual Install URL: http://wordpress.org/extend/plugins/widgetlogic/
Automatic Install search term: Simple Tags
Geek level: WP Ninja
Configuration location: None
Used in: Administrator
Really, most blogs only contain three different types of pages, namely, the home page, the post page, and the category page, hence the lack of a need to have different widgets on different pages. However, if you're building a full blown website (not just a blog) using WordPress, then the need to target specific widgets to a given page is most helpful. Widget Logic allows you to target specific pages and other conditions, that, when met, will display a specific widget.
Once installed, every widget you put on your blog's sidebar will now have a new field at the bottom called WP Logic—inside this text box is where...