well after finally reading your signature, i figured i'd spend 5 minutes and do this one
PHP Code:
$randname = $DB_site->query_first('SELECT username, userid FROM user ORDER BY rand() LIMIT 1');
print '<a href="./VBFOLDER/member.php?s='.$session['sessionhash'].'&action=getinfo&userid='.$randname['userid'].'">'.$randname['username'].'</a>';
have fun

just put that wherever you want