Denis

Allows your users to add posts with images by anonymous, without any registration and authorization. 
From any page of your blog, where you place the form.
<ul>
<li>You can disable image upload option at plugin options page.</li>
<li>You can set your own template for generating post. Simply from options page.</li>
</ul>
<h3>Thanks</h3>
Uses <a href="http://blueimp.github.io/jQuery-File-Upload/" title="jQuery File Upload" rel="nofollow ugc">jQuery File Upload</a> by Sebastian Tschan for image transfer.

Azz Anonim Posting

Allows your users to add posts with images by anonymous, without any registration and authorization.

Dion Hulse

** Support for this plugin is NOT offered, This plugin still however works. Please don’t expect support requests to be answered, or “This doesn’t work” reviews to be responded to. **
Revision Control is a plugin for WordPress which gives the user more control over the Revision functionality.
The plugin allows the user to set a site-global setting (Settings -> Revisions) for pages/posts to enable/disable/limit the number of revisions which are saved for the page/post. The user may change this setting on a per-page/post basis from the Revisions Meta box.
The plugin also allows the deletion of specific revisions via the Revisions post metabox.

Revision Control

Revision Control allows finer control over the Post Revision system included with WordPress

Azz Anonim Posting vs Revision Control