PoseLab

A simple plugin that displays a list of all categories except those selected in widget preferences. Unlike other similar plugins like “Almost All Categories Widget”, Categories but exclude uses the latest version of WordPress Widget API, which is multi-widget, which lets you use the wigdet more than once. Mostly, I created the plugin to use it with the plugin “WPML” along with “Widget Logic” to use the same widget for each language.
This will allow you to create a custom category list which will show the categories you want, and will hide the categories you do not want. For example, say you have a particular category you don’t want to be displayed named “Announcements”. You can use this plugin to display all of your other categories, except the category “Announcements”. You are not limited to just excluding one category; you can exclude multiple categories.
Languages:
<ul>
<li>Spanish (es_ES) – <a href="http://poselab.com/" rel="nofollow ugc">PoseLab</a></li>
<li>French (fr_FR) – <a href="http://www.tradpress.fr/" rel="nofollow ugc">TradPress</a></li>
</ul>
If you have created your own language pack, or have an update of an existing one, you can <a href="mailto:javierpose@gmail.com" rel="nofollow ugc">send me</a> your gettext PO and MO so that I can bundle it into the Categories but exclude. You can download the latest POT file <a href="https://plugins.trac.wordpress.org/browser/categories-but-exclude-widget/trunk/categories-but-exclude.pot" rel="nofollow ugc">from here</a>.

Categories but exclude

Displays all categories except those selected in widget preferences.

mosseh

For more information see http://www.amoss.me.uk/tag/selective-reading/
Features
<ul>
<li>Category widget is updated with show/hide links for each category.</li>
<li>Works for unregistered users (using cookies)</li>
<li>Works for hierarchical categories</li>
</ul>
TODO/Planned Features
<ul>
<li>AJAX Reload post list after change of selection (currently refreshes whole page)</li>
<li>Configuration for contents of show/hide etc.</li>
<li>Hide links when javascript is disabled (plugin depends on javascript)</li>
<li>Tooltip when first clicked hide or show</li>
<li>Strikethrough category name when hidden</li>
<li>Notify when can’t unhide child due to hidden parent</li>
<li>Clearer indication of hierarchical hiding when hierarchical display is disabled?</li>
<li>Better error checking</li>
<li>Autoformat code</li>
<li>Support for WP super cache – does not currently function for unregistered users with this plugin enabled</li>
</ul>

Selective Reading

Allows website visitors to deselect categories they don't want to see on your blog.

Categories but exclude vs Selective Reading