Remove all the default WordPress dashboard widgets.

wp-remove-dashboard.php

<?php
/*
Plugin Name: Remove Dashboard Meta Boxes
Plugin URI: http://pmg.co/category/wordpress
Description: Removes the default dashboard widgets from the WordPress admin.
Author: Christopher Davis
Author URI: http://pmg.co/people/chris
License: GPL2
*/

add_action( 'wp_dashboard_setup', 'pmg_rm_meta_boxes' );
function pmg_rm_meta_boxes()
{
	/**
	 * Removes the "Right Now" widget that tells you post/comment counts
	 * and what theme you're using.
	 */
	remove_meta_box( 'dashboard_right_now', 'dashboard', 'normal' );
	
	/**
	 * Removes the recent comments widget
	 */
	remove_meta_box( 'dashboard_recent_comments', 'dashboard', 'normal' );
	
	/**
	 * Removes the incoming links widget.
	 */
	remove_meta_box( 'dashboard_incoming_links', 'dashboard', 'normal' );
	
	/**
	 * Removes the plugins widgets that displays the most popular,
	 * newest, and recently updated plugins
	 */
	remove_meta_box( 'dashboard_plugins', 'dashboard', 'normal' );
	
	/**
	 * Removes the quick press widget that allows you post right from the dashboard
	 */
	remove_meta_box( 'dashboard_quick_press', 'dashboard', 'side' );
	
	/**
	 * Removes the widget containing the list of recent drafts
	 */
	remove_meta_box( 'dashboard_recent_drafts', 'dashboard', 'side' );
	
	/**
	 * Removes the "WordPress Blog" widget
	 */
	remove_meta_box( 'dashboard_primary', 'dashboard', 'side' );
	
	/**
	 * Removes the "Other WordPress News" widget
	 */
	remove_meta_box( 'dashboard_secondary', 'dashboard', 'side' );
	
}