My Gravatar PHP Function

// If you'd like to implement Gravatar on your site and want a simple function to use,
// feel free to use this function I made for some of my sites.

// Example - Default settings:
// <img src="<?php echo gravatarURL($userEmail); ?>" />

// Example - Custom size, default image, and rating:
// <img src="<?php echo gravatarURL($userEmail, 100, 'http://some-site.com/images/default_user.png', 'g'); ?>" />


function gravatarURL($email, $size = 80, $defaultImage = "identicon", $rating = "pg") {
    $emailHash = md5(strtolower(trim($email)));
    $url = "http://gravatar.com/avatar/{$emailHash}?s=$size&d=$defaultImage&r=$rating";
    return $url;
}