Getting the friends like @nfvs describes is a good way. It outputs a multi-dimensional array with all friends with attributes id and name (ordered by id). You can see the friends photos like this:
foreach ($friends as $key=>$value) {
echo count($value) . ' Friends';
echo '<hr />';
echo '<ul id="friends">';
foreach ($value as $fkey=>$fvalue) {
echo '<li><img src="https://graph.facebook.com/' . $fvalue->id . '/picture" title="' . $fvalue->name . '"/></li>';
}
echo '</ul>';
}