Drag & Drop Featured Image is a WordPress plugin by plizzo made to save you time when setting a featured image. What it does is simple, it replaces the default “Set featured image” metabox with a new one containing a Plupload drop area just like the one found in the media uploader.
Since it uses the default WordPress functions it will compress all sizes just as the regular upload method would and it also respects any custom image sizes.
Download: http://wordpress.org/extend/plugins/drag-drop-featured-image/
