Meitar

digiacom

Display and manage volunteer projects for any purpose.
<ul>
<li>Registers custom post type <code>wp-vpm-projects</code></li>
<li>Registers metaboxes to the editing screen for project meta fields</li>
</ul>
This plugin is in beta, and is not yet appropriate for a production site.
Important features like post ordering and administrative settings are absent.
That said, perhaps you will find it useful!
This plugin is in use over at <a href="http://www.volunteerwild.org" title="Conservation stewardship in Durango, Colorado" rel="nofollow ugc">Volunteer Wild</a>

WordPress Volunteer Project Manager

Display and manage volunteer projects for any purpose.

ajit prabhakar

This is simple volunteer registration plugin. 
The User will appear in Users menu. After login user can edit their profiles. 
USE echo do_shortcode( ‘volunteer_registration_form’ ); in template and theme. 
USE [volunteer_registration_form] in pages and posts.

Volunteer Registration

Simple Plugin

This is simple volunteer registration plugin.

WordPress Volunteer Project Manager vs Volunteer Registration