This plugin adds the Retaggr functionality to your blog.
** IDENTITY **
The Retaggr Profile Card is about identity – its a virtual, interactive business card which you can customize as you wish. 
Widgets can be added into it to show posts from your blog,music you’re currently listening to, allow communication via IM, or pretty much 
Consolidate all your identity widgets on your blog into one, and add custom widgets from anywhere on the web. Built-in widgets include support for Twitter, FriendFeed, Flickr, MSN, and Disqus, to name a just a few.
People use Retaggr Profile Cards to bring traffic to their blog and express their identity. A demo can be found at retaggr.com.
Installing this plugin means :
<ul>
<li>Your visitors can leave their retaggr card when they comment on your posts</li>
<li>When referring to other people in a post, you can insert their profile card, instead of just linking to their blog. </li>
<li>Your card is attached to your posts</li>
</ul>
These unintrusive enhancements add context to your posts – bringing fun and useful functionality to your site, while keeping readers from unnecessarily navigating away to find out more about the person in question.
retaggr also allows you to add site specific widgets to card on your site – explore retaggr.com for more details.
** IMAGE TAGGING **
This plugin also gives your blog powerful image tagging functionality. Your users can tag people in any image on your blog, much like you would on a social network. 
Just drag around the person in the image and select the name from your address book, which is integrated with your email or Facebook. 
Mousing over the person then shows their retaggr Profile Card. There are full moderation and notification options.
You do not need to modify any of your template files — just activate the plugin, and set your options on retaggr.com.
<h3>Feedback/ Help</h3>
Don’t hesitate to drop us a line via the retaggr.com website if you need anything at all.

retaggr

This plugin adds the Retaggr functionality to your blog.

psqr

Virtual Public Squares are digital spaces for open communication. Publishers establish identities, preferably on their own websites, and use those identities to attach verifiable provenance to content with cryptographic signatures. The signed content is broadcast into one or more Virtual Public Squares. Once signed and broadcast, the content becomes public and portable.
The content, with provenance, may move from one Virtual Public Square to another, may be indexed and made searchable, and may be displayed to readers in feeds, curated lists, or search results. Every time a Virtual Public Square displays content, the publisher’s cryptographic signature is attached to that content and can be verified.
In the event that any Virtual Public Square blocks content from a publisher, that publisher remains free to broadcast that content to any other Virtual Public Square. 
Similarly, publishers are free to set up their own Virtual Public Squares and ingest the content from existing Virtual Public Squares. In this fashion, Virtual Public Squares impose practical disincentives to censorship without infringing on the rights of speech or association of any of the participants.
The primary use of Virtual Public Square technology is to acquire content from specified publishers without third party interference. This will often appear in the format of a news feed. The first commercial use of Virtual Public Square data is to populate widgets on websites containing curated content from a set of publishers that seek to cross-promote each other to keep readers engaged and maximize audience attention.
<h3>Required PHP Extensions</h3>
The following PHP extensions are required to update and delete DIDs with an API call:
<ul>
<li>json</li>
<li>mbstring</li>
<li>openssl</li>
</ul>

Virtual Public Square

Virtual Public Squares operate on identity. Add self-hosted, cryptographically verifiable, decentralized identity to your site and authors.

retaggr vs Virtual Public Square