Auto rendered images from external links
CKeditor has the ability to add an image to a text field using its url:


  This module will allow Drupal to replace textarea fields with the
  CKEditor - a visual HTML editor, usually called a WYSIWYG editor. This
  HTML text editor brings many of the powerful WYSIWYG editing functions
  of known desktop editors like Word to the web. It's very fast and
  doesn't require any kind of installation on the client computer.