fitztrev

Comment Image Embedder is a very simple plugin that, once installed, lets your visitors add an image to their comments.
It’s rather common for a WordPress user to ask how visitors can embed images in the comments section of their blogs.
This plugin will add a link just below the comment box that a user can click on. When clicked, a prompt will appear for the user to enter the URL of the image. It will then be added to their comment.
Trevor Fitzgerald 
http://trevorfitzgerald.com/

Comment-Images

Comment Image Embedder is a very simple plugin that, once installed, lets your visitors add an image to their comments.

This plugin allow you to grab image from remote url and save into your own wordpress media library. By doing so, you never worried if the remote image was removed by its owner. This also save you steps to download the image to local computer and upload again to your own wordpress.
After grabbing the image, wordpress will prompt you either to “insert into post” or “change attributes” just like after you upload an image. Renaming is available.

Grab & Save

This plugin allow you to grab and save the image from remote url into your own wordpress media library.

Comment-Images vs Grab & Save