[Adrian Schneider]

Where do you want it displayed?
Off the top of my head, place something like in the file you want it:

PHP Code:

$newestmembers = $DB_site->query("
    SELECT userid, username
    FROM user
    ORDER BY userid DESC
    LIMIT 5
");
$shownewest=$DB_site->fetch_array($newestmembers))
{
    $counter++;
    $newuserid = $shownewest['userid'];
    $newusername = $shownewest['username'];
    $newestbit .= "<a href=\"member.php?u=$newuserid\">$newusername</a>";
    if ($counter < 5)
    {
        $newestbit .= ", ";
    }
} 


Then place $newestbit in your template where you want it (it will list the last 5 users seperated by commas).