wpmu list most recent posts

seems like the easiest way might to use this (or a few other options) as a plugin:

• http://wpmudev.org/project/Most-recent-posts—updated or
• http://wpmudev.org/project/List-All-Posts

then add this plugin to execute the php within a post:

• http://www.hongkiat.com/blog/execute-php-in-wordpress-post-page-and-widget-sidebar/

and there is somewhere else another wpmu plugin to make the above plugin not available to other users.