Find Users in a Database

select 
left(rtrim(case u1.islogin when 1 then u1.name end), 30) 'Login Name', 
left(rtrim(u1.name), 30) 'User Name', 
left(rtrim(u2.name), 30) 'Group Name' 
from sysusers u1, sysusers u2 
where u1.gid = u2.uid and 
u1.sid is not null and 
u1.name not in ('guest', 'dbo', 'Administrator')