http://www.hackingethics.com/blog/2010/09/04/how-to-enable-featured-image-in-wordpress/
http://wpcanyon.com/tutorials/how-to-use-the-post-thumbnail-feature-in-wordpress-2-9/
http://wpengineer.com/1930/the-ultimative-guide-for-the_post_thumbnail-in-wordpress-2-9/
http://themehybrid.com/support/topic/prettyphoto-for-the_post_thumbnail
http://austinmatzko.com/wordpress-plugins/filosofo-custom-image-sizes/
http://www.studiopress.com/genesis-tips/how-to-create-a-new-featured-image-size.htm