Alex Moss

Google+ comments was introduced in April 2013 to blogger.com users. This plugin lets you add Google+ comments to your WordPress site!
Simply install the plugin and follow the instructions on the Settings page.
<ul>
<li><a href="http://3doordigital.com/wordpress/plugins/google-plus-comments/" rel="nofollow ugc">Google+ Comments</a> Plugin homepage.</li>
<li>More <a href="http://3doordigital.com/wordpress/plugins/" rel="nofollow ugc">WordPress Plugins</a>.</li>
</ul>
You can also insert the comment box as a shortcode into any post, page or template and use your own settings for each time you do it! Simply use the shortcode [gp-comments]

Google+ Comments

The Google+ Comments WordPress plugin makes it easier for you to setup, administer and customise Google+ comments from your WordPress site.

mhawksey

<a href="http://www.rsc-ne-scotland.org.uk/mashe/utitle/" rel="nofollow ugc">uTitle</a> is an experimental tool which uses Twitter to allow users to make free and timeline based comments on YouTube videos. The original concept is <a href="http://www.rsc-ne-scotland.org.uk/mashe/2010/06/convergence-youtube-meets-twitter-in-timeline-commenting-of-youtube-videos-using-twitter-utitle/" rel="nofollow ugc">explained in detail in this blog post</a>, but the basic idea is video are played in custom interface which lets users ‘tweet’ comments. Part of each tweet includes a hashtag linking it to a specific YouTube video and a timestamp from the current point in the video. Tweets are stored in the <a href="http://twapperkeeper.com/" rel="nofollow ugc">TwapperKeepr</a> and temporarily cached on the uTitle site. When a video is replayed in the uTitle interface existing comments appear at the timed points as subtitles and users can also use the timed tweets to jump to part of the video <a href="http://www.youtube.com/watch?v=RVp2F6tDWfw" rel="nofollow ugc">(see this video for a demonstration)</a>
This plugin allows you to easily embed commented YouTube videos by enabling a uTitle specific short code (e.g. [utitle mode=1 comment=yes]RVp2F6tDWfw[/utitle]). Options are available to choose the type of player (see Screenshots) and as well as a choice to provide a link to invite users to add their own comments.
uTitle essentially works as the glue combining YouTube and Twitter, subsequently there is no direct control over moderating comments (but it does via TwapperKeepers configuration conform to Twitter’s deletion policy).
This plugin and the uTitle site are not affiliated with YouTube or Twitter.

uTitle Plugin

The uTitle Plugin  allows timeline commenting of YouTube videos using Twitter by integrating with the experimental uTitle tool

Google+ Comments vs uTitle Plugin