Peter Westwood

This plugin allows you to run loops within your WordPress templates where you query for children of the current page.
The plugin extra arguments to the list of arguments supported by query_posts().
The query argument <code>child_of</code> is used to add a WHERE to the database query to limit the pages returned to those with a post_page equal to the argument provided.
The query argument <code>child_limit</code> is used to limit the number of pages returned.
The query argument <code>child_offset</code> is used to offset the limiting to allow for pagination if required.

PJW Query Child Of

This plugin allows you to run loops within your WordPress templates where you query for children of the current page.

jeff.cave

This plugin provides a “Sub Page” widget. It lists all of the pages which are children of the current page. If there are no children, it will not display.
Options include:
<ul>
<li>title (obviously)</li>
<li>“No Sub-pages” text instead of blank (configurable)</li>
<li>hide widget when no sub-pages</li>
<li>show siblings when no sub-pages</li>
</ul>
While this is a small widget, I have attempted to make this as configurable as possible, with clean and efficient code (this is a small widget, and shouldn’t slow your site down).

PS Sub-pages

Shows the child pages of the current page. Configurable title, show siblings (or not), and "no child" text

PJW Query Child Of vs PS Sub-pages