Create Parents / Children Relationship between different post types checking one or more parent.
Use WordPress' nav menu system to create left/right widget flyouts, with support for Superfish
This plugin gives a quick example of a generic parent child relationship custom post type.
Allows you to use query_posts to list the children of a page.
This is a plugin to hide pages from navigation and/or search results using custom fields, parent and child pages are supported too
This plugin will display links to posts from a category in a widget that will be assigned to a page, and will display on that page and on all child pa
A text widget which allows the user to choose a page for it to be a child of. The widget will only show on that page and all child pages.
This plugin is designed to be a page menu for people using WordPress as a CMS
Remove Parents is a tiny plugin which remove "category" and parent categories from permalink.