azurecurve

featured-image shortcode allows a floating featured image to be placed at the top of a post. Default settings can be entered to simplify the use of the plugin.
When used several parameters are available for use: 
1. image – to use an image other than the default 
2. title – set a title on the image (will appear in the tooltip) 
3. alt – enter the alt text for when the image cannot be displayed 
4. taxonomy – enter a category or tag name or slug to have a hyperlink added to the image 
5. is_tag – set to 1 for when the taxonomy should be a tag instead of a category
This plugin is multi-site compatible.
This plugin supports language translations. If you want to translate this plugin please sent the .po and .mo files to wordpress.translations@azurecurve.co.uk for inclusion in the next version (full credit will be given). The .pot fie is in the languages folder of the plugin and can also be downloaded from the plugin page on http://development.azurecurve.co.uk.
Current translations: 
Serbian (sr_RS) translation by Borisa Djuraskovic of <a href="http://www.webhostinghub.com/" rel="nofollow ugc">Web Hosting Hub</a>

azurecurve Floating Featured Image

Shortcode allowing a floating featured image to be placed at the top of a post; this plugin is multi-site compatible.

tsaiid

Featured Image via URL is a plugin to generate the featured image of post from the image url specified. 
The image will be fetched back and saved into the Media Library with all supported sizes. 
If the featured image is already present, the plugin will do nothing.
This plugin is modified from Auto Post Thumbnail by adityamooley.
For more details, see http://tsai.it/project/wordpress-plugins/featured-image-via-url/

Featured Image via URL

Automatically generate the Featured Image from the specified image url in post.

azurecurve Floating Featured Image vs Featured Image via URL