Artberri

When someone comments on your blog and writes a comment with his/her URL, is leaving more information than you think. This plugin displays web pages and profiles of those users in the dashboard, so you can add them as friends if you are in the same social network.
This is possible thanks to the Google Social Graph API. The profiles are showed because the commenter claims them as its owner on his web linking them with <code>rel="me"</code>. The ones which are with italic font are not reliable and they could not be of the user.
Comments, questions and bug reports are welcome: <a href="http://www.berriart.com/meet-your-commenters/" title="Meet Your Commenters" rel="nofollow ugc">http://www.berriart.com/meet-your-commenters/</a>

Meet Your Commenters

Displays web pages and social networks' profiles of your commenters in the dashboard.

soychuy

YouTube Thumbnail to Featured Image, as its name says, is a plugin that helps you to set a YouTube video thumbnail as a featured image of a post. The user just have to set a YouTube video URL and the plugin will do the rest.
The video thumbnail will be imported to your media library, so you can use it anywhere else.

Youtube Thumbnail as Featured Image

Use a YouTube Thumbnail as a Featured Image for a WordPress Post. You only have to set a YouTue Video URL and the plugin does the rest.

Meet Your Commenters vs Youtube Thumbnail as Featured Image