Found it!
EXEC sp_addlinkedserver 'ADSI', 'Active Directory Services 2.5', 'ADSDSOObject', 'AD Provider'
grant select on corpsysad_allusers to public
select * from corpsysad_allusers
create view corpsysad_allusers as
SELECT name
FROM OPENQUERY( ADSI, '
SELECT name
FROM ''LDAP://163.232.12.200/CN=Application Users,DC=ppl2kdv''')
where ppl2kdv is the root node of my AD (others may include the complete .com.au or whatever, if so, your need DC=com, DC=au for example. Check this via the AD Maintenance GUI on your server. CN is for container, OU is for org unit.
Chris Kempster
www.chriskempster.com
Author of "SQL Server Backup, Recovery & Troubleshooting"
Author of "SQL Server 2k for the Oracle DBA"