WP Thumbs is a voting plugin that allows users to like or dislike posts and pages.
Features:
*Thumbs up or down mode
*Like button only mode
*Like/Dislike button mode
*Graph of clicks
*Customizable via CSS
*WPMU Compatible
*User only or cookie based security.
*Placement of buttons
*Page or Post Placement
Future:
*IP based security
*Reset likes/dislikes from wp-admin editor
