Utiliser Gravatar

gravatar.php

<?php
    /*------------------------------------------------*\
        @email - Email address to show gravatar for 
        @size - size of gravatar 
        @default - URL of default gravatar to use 
        @rating - rating of Gravatar(G, PG, R, X) 
    \*------------------------------------------------*/
    function show_gravatar($email, $size, $default, $rating) {  
        echo '<img src="http://www.gravatar.com/avatar.php?gravatar_id='.md5($email).  
        '&default='.$default.'&size='.$size.'&rating='.$rating.'" width="'.$size.'px"  
        height="'.$size.'px" />';  
    }