This plugin provides an easy way to incorporate a bug/enhancement tracking system to a WordPress site. By adding a shortcode to a page, users will be able to display a bug list and allow visitors to submit new bugs / enhancements. The plugin will also provide search and sorting capabilities. A captcha and approval mechanism will allow the site admin to avoid spam.
You can try it out in a temporary copy of WordPress here.
This plugin is available for download to be used on your WordPress self-hosted installation.