With this little snippet you can add custom image sizes to media insert dialog box.
image_size_names_choose allows modification of the image size lists so that you can place a custom option within the media library.
this months featured snippets
If you would like to require that all posts have a featured image before they can be published add this snippet to the functions.php of your wordpress theme. When you try and publish a post without a featured image you get an admin message “You must select Featured Image. Your Post is saved but it can not be published.” Great way to ensure all your posts have a featured image before they are publish.read more
Disqus outputting JS on parts of your wordpress website you don’t want? Adding this snippet to the functions.php of your wordpress theme will only output JS on is_singular posts or pages where comments are available.read more