mores

MetaBackGround will let you specify a post background by adding a custom field. This is not the sorcerer’s stone, but some users are not comfortable with php and editing of theme files, so all they need to do is install this plugin.

MetaBackGround

I once created this plugin for someone ... they needed to set backgrounds on a per-post basis.

awssoft

Magic Edge Lite – Image Background Remover provide easy way to remove background from complex photo. 
It’s unbelievable easy to use. Just in several steps your photo became transparent. 
Also, this is a first and only one photo background remover plugin for the WordPress, on the whole market!
Videos:
<ul>
<li>We made several videos that show different tehniques. 
<a href="http://www.awssoft.com/magic-edge/videos.php" title="Magic Edge - video" rel="nofollow ugc">Open Videos page</a>.</li>
</ul>
Features:
<ul>
<li>Easy to use interface</li>
<li>Support images with complex, white, gray or gradient background</li>
<li>MagicEdge tools</li>
<li>Image conversion on the client side</li>
<li>Auto conversion from JPG, GIF to PNG</li>
<li>Download or send to server</li>
<li>Preview before save</li>
<li>Undo and Redo</li>
<li>Zoom and Pan</li>
<li>Cross-browser support</li>
<li>Edge Shadow <a href="http://www.awssoft.com/magic-edge/" title="Magic Edge" rel="nofollow ugc">Magic Edge Full version</a></li>
<li>Edge Feather <a href="http://www.awssoft.com/magic-edge/" title="Magic Edge" rel="nofollow ugc">Magic Edge Full version</a></li>
<li>Auto/Manual Crop <a href="http://www.awssoft.com/magic-edge/" title="Magic Edge" rel="nofollow ugc">Magic Edge Full version</a></li>
</ul>

Magic Edge – Lite

Magic Edge Lite - Image Background Remover provide easy way to remove background from complex photo.

MetaBackGround vs Magic Edge – Lite