In one of my projects, I converted WordPress into a reporting engine, which is used at 20 car dealerships to track Internet sales.  During development, I found that I was writing the same code over and over again for the jQuery Tablesorter plugin, which allows you to sort tables using a simple JavaScript call.

First, I would have to queue the script file, then add the appropriate JavaScript. To ensure the JavaScript was executed at the right time, I had to create a function to use it with add_action().  I found this to be tedious and unnecessary, and wrote a simple helper function to remedy this.  The following function was added to /wp-admin/includes/template.php, but if you use it, it will most likely go in a plugin or theme include.  This will prevent it from being overwritten during WordPress upgrades.

/**
 * Make all tables with the specified identifier sortable using the jQuery Tablesorter plugin.
 * 
 * @uses wp_enqueue_script() To enqueue the jQuery Tablesorter script.
 *
 * @param string $identifier jQuery selector (.sortable, #element_id, table, etc.)
 * @param array $args Default is empty string. Array of arguments to pass to $.tablesorter()
 * @return void
 */
function make_table_sortable($identifier, $args = '') {
	global $sortable_tables;
	
	if ( in_array($identifier, (array)$sortable_tables) )
		return;
	
	wp_enqueue_script('jquery-tablesorter');
	
	$sortable_tables[] = array(
		'identifier' => $identifier,
		'args'		 => $args
	);
	
	add_action('admin_print_footer_scripts', '_make_table_sortable');
}

function _make_table_sortable() {
	global $sortable_tables;
		
	if ( count( (array)$sortable_tables ) <= 0 )
		return;
?>
<script type="text/javascript">
<?php
	foreach ($sortable_tables as $sortable_table) {
		if ( !is_array($sortable_table['args']) ) {
			$arguments = '';
		} else {
			$arguments = '{';
			
			$args_count = sizeof($sortable_table['args']);
			$i = 0;
			foreach ($sortable_table['args'] as $k => $v) {
				$arguments .= $k . ': ' . $v;
				if (++$i != $args_count) $arguments .= ', ';
			}
			
			$arguments .= '}';
		}
?>
$('<?php echo esc_js($sortable_table['identifier']); ?>').tablesorter(<?php echo esc_js($arguments); ?>);
<?php } ?>
</script>
<?php
}

Below exemplifies usage of the make_table_sortable() function:

// Sort tables with class 'sortable', first and second columns in ascending order with first taking precedence.
make_table_sortable('.sortable', array('sortList' => '[[0,0], [1,0]]'));

// Sort table with ID 'sortable', first column in ascending order. Turn debugging on.
make_table_sortable('#sortable', array('sortList' => '[[1,0]]', 'debug' => 'true'));

Download the jQuery Tablesorter Plugin