Identifying orphaned users

I ran sp_helptext to get the code for the report section of sp_change_users_login:

select UserName = name, UserSID = sid from sysusers
    where issqluser = 1 
    and   (sid is not null and sid <> 0x0)
    and   (len(sid) <= 16)
    and   suser_sname(sid) is null
    order by name

I then converted that to SQL Server 2005/2008 code:

SELECT UserName = dp.name, UserSID = dp.sid
FROM sys.database_principals dp
WHERE dp.type = 'S'
    AND (dp.sid is not null AND dp.sid <> 0x0)
    AND (LEN(dp.sid) <= 16)
    AND SUSER_SNAME(dp.sid) is null
ORDER BY dp.name