LordPretender

<p>This plugin allow you to add files into your media library without having to upload them. So, you will be able to share, for example, your files into your Google Drive.<br />
This also save you steps to download the image to local computer and upload again to your own WordPress.</p>
<h4>Features</h4>
<ul>
<li>Automatically downloads and adds the file to the media library.</li>
<li>After the uploading is successful, you are redirected to the edit screen</li>
<li>A new dropdown list is available in the media library to let you display only uploaded files, not uploaded files, …</li>
</ul>


Add Media from URL

large chunks of code taken from the much better original here:

https://en-au.wordpress.org/plugins/lh-add-media-from-url/

IMO it unethical to use this plugin

A crappy clone of the original

Let you add media files into your media library without having to upload them.

singpolyma

<p>Detects hCards, Facebook links, and Wink.com search results and allows the user to add the detected people to their WordPress links system.</p>


Friend Bookmarklet

Generates a bookmarklet that makes it easier to add friends to the WordPress links system.

Add Media from URL vs Friend Bookmarklet