This topic is marked as "resolved"... yet there is nothing other than the original post (and now, this first comment).
Further (Google) search turned up a solution: http://gravitationalpull.net/wp/?p=1466
This solution is good for small nav menus, i.e., no child pages. The cool "Menu" administration in WP's dashboard does not appear to accommodate child pages.
I've poured through the codex documentation, found the WP 2.0 solution on how to exclude pages from the list: http://codex.wordpress.org/Template_Tags/wp_list_pages
... but,alas, Twenty Ten does not use the simple wp_list_pages function.
Any code-savvy samaritan want to chime in with a solution? Is this where the use of filters come into play?