Generic WordPress caching with Transients API

cached_data.php

<?php

/**
 * Get data with caching
 * 
 * Change function name, transient name, and cache timeout if necessary.
 * Populate $my_data, obviously.
 * "refresh" query parameter useful for manual refreshing.
 */
function pilau_get_my_data() {
	if ( isset( $_GET['refresh'] ) || false === ( $my_data = get_transient( 'pilau_my_data' ) ) ) {
		$my_data = array();
		set_transient( 'pilau_my_data', $my_data, 60*60*24 ); // Cache for 24 hours
	}
	return $my_data;
}