Hi
I have a new plugin of wordpress which this plugin automatically upload external images of a post to wordpress upload directory.
http://wordpress.org/extend/plugins/auto-upload-images/
full description of plugin:
When you want to save post, this plugin search for images url which exists in post and automatically upload external images to wordpress upload directory and replace external link with your link.
Automatically add image to Media Library and Attach to post.
If you may please write about this plugin in weblogtoolscollection.com :)
thank you