http://justintadlock.com/archives/2009/05/06/custom-taxonomies-in-wordpress-28
http://justintadlock.com/archives/2009/11/09/excerpts-and-taxonomies-for-pages-in-wordpress-2-9
http://justintadlock.com/archives/2009/11/16/everything-you-need-to-know-about-wordpress-2-9s-post-image-feature
http://justintadlock.com/archives/2010/02/02/showing-custom-post-types-on-your-home-blog-page
http://webdevstudios.com/support/wordpress-plugins/category-mapping-plugin-for-wordpress-mu/
http://wordpress.org/extend/plugins/category-posts/
http://premium.wpmudev.org/project/post-indexer
http://mu.wordpress.org/forums/topic/9913
http://wordpress.org/extend/plugins/ajax-login-widget/