WordPress › Sibling Pages « WordPress Plugins

Sibling Pages

Generates and registers a widget that generates a list of links to sibling pages (pages that have the same parent page)

This plugin depends on setting some pages to have the same "parent" page.
If page A, B and C all have the same parent page, then the plugin will generate a list of links to page A, B and C whenever you are on any one of those pages, or whenever you are on the parent page.
The parent page will be listed first in the list of siblings, then the sibling pages in apha order by page title.