Facebook, LinkedIn and Google+ have this useful feature called "Link Preview":
When you paste a URL into a post, Facebook's server automatically grabs the title and description from the linked website and lets you select a thumbnail image from those available on the linked site.
This saves so much time that you would otherwise spend finding, copying, pasting, resizing and uploading an image for your post.
WordPress should also have this feature. I would recommend it work in the following way:
1. When you are in the WordPress editor, you click a special button called "Generate Link Preview".
2. WordPress brings up a new small window, which asks you to enter enter the URL into a text field, then you click OK.
3. WordPress then retrieves the title, description and thumbnail images from the destination site and then displays a draft link preview in the small window.
4. The user can make any final edits to the link preview, i.e. editing or removing the title, description or choose a different thumbnail image. Once the user is done, they click on a a button named "Insert", which pastes a block of HTML into the editor.
Here is a free third-party implementation of this feature written in PHP and jQuery. I am sure that it could be adapted to WordPress