Enrico Sorcinelli

Taxonomies Sortable allow to sort non-hierarchical taxonomy terms associated to objects by drag&drop them on the administration interface.
<h3>Usage</h3>
Once the plugin is installed you can make a taxonomy sortable in the following ways:
<ul>
<li>Programmatically by adding <code>'sortable' => true</code> argument in <code>register_taxonomy()</code>.</li>
<li>Programmatically by using <code>taxonomies_sortable</code> filter below.</li>
<li>Using the Settings->Taxonomies Sortable administration screen by selecting non-hierarchical taxonomies you want to make sortable.</li>
</ul>
Note that making a taxonomy sortable, implicitly means also setting <code>sort => true</code> for that taxonomy.
<h3>Hooks</h3>
<code>taxonomies_sortable</code>
Filter allowing to programmatically set sortable taxonomies.
<pre><code>apply_filters( 'taxonomies_sortable', array $taxonomies )
</code></pre>
<code>taxonomies_sortable_admin_settings</code>
Filter allowing to display or not the plugin settings page in the administration.
<pre><code>apply_filters( 'taxonomies_sortable_admin_settings', boolean $display )
</code></pre>

Taxonomies Sortable

Allows to sort taxonomy terms associated to objects.

wolfoz

Improved use of hierarchical taxonomy metaboxes for products, posts, etc. 
Automatically select parent elements when an element is selected and automatically deselect child elements when an element is deselected. 
Support for custom taxonomies. Highlighting the changed state of elements.

WolfOz taxonomy mbtree

Tree view for metaboxes of taxonomies (products, publications, etc.)

Taxonomies Sortable vs WolfOz taxonomy mbtree