T5 Inspect Queries Adds a list of all queries at the end of each file.

inspect-queries.php

<?php
/**
 * Plugin Name: T5 Inspect Queries
 * Description: Adds a list of all queries at the end of each file.
 *
 * Add the following to your wp-config.php:

define( 'WP_DEBUG',         TRUE );
define( 'SAVEQUERIES',      TRUE );

 */

add_action( 'shutdown', 't5_inspect_queries' );

/**
 * Print a list of all database queries.
 *
 * @wp-hook shutdown
 * @return  void
 */
function t5_inspect_queries()
{
	global $wpdb;

	$list = '';

	if ( ! empty( $wpdb->queries ) )
	{
		$queries = array ();
		foreach ( $wpdb->queries as $query )
		{
			$queries[] = sprintf(
				'<li><pre>%1$s</pre>Time: %2$s sec<pre>%3$s</pre></li>',
				nl2br( esc_html( $query[0] ) ),
				number_format( sprintf('%0.1f', $query[1] * 1000), 1, '.', ',' ),
				esc_html( implode( "\n", explode(', ', $query[2] ) ) )
			);
		}

		$list = '<ol>' . implode( '', $queries ) . '</ol>';
	}

	printf(
		'<style>pre{white-space:pre-wrap !important}</style>
		<div class="%1$s"><p><b>%2$s Queries</b></p>%3$s</div>',
		__FUNCTION__,
		$wpdb->num_queries,
		$list
	);
}