kamiel79

Adding explicit thumbnails (featured images) to your content takes time. Even if you don’t add your own photography, you’d still need to go to search.creativecommons.org or so. This plugin hooks into the thumbnail URL and changes this with an image from the Flickr API, based on the tags in your post. If Flickr couldn’t find anything, it will return an empty string. I have achieved good results, with posts that all of a sudden had a rather adequate thumbnail.
[Flickr images might have licensing issues, so I recommend to use this plugin only on personal sites]

Flickr Fallback Thumbnail

Automatically grab a fallback featured image if your post doesn't have one!

Chris Klosowski

This plugin adds the shortcode <code>[plugin_banner]</code>, so you can quickly and easily display the banner image from the WordPress.org repository for the given plugin slug.
For example, to display the banner image of this plugin you would use: 
 [plugin_banner slug=”wp-plugin-banner”]
By default images are not linked but if you add <code>link=true</code> into the argument list the image will be clickable and take the visitor the plugin page in the WordPress.org plugin directory.
The image status and plugin title is all pulled dynamically from the WordPress.org API, this data is cached for 1 week to help with performance.
List of supported attributes: 
 slug – The slug to the WordPress plugin (found in the URL in the WordPress.org plugin directory) 
 link – If the image should be linked to the plugin in the WordPress.org directory. Options: true|false (default) 
 title_wrapper – What HTML element to wrap the title of the plugin with. Supported: h2 (default), h3, h4, h5, em, strong, span, p

WP Plugin Banner

Easily display the banner image and title of a plugin on the WordPress.org Directory within your WordPress posts.

Flickr Fallback Thumbnail vs WP Plugin Banner