a question regarding nt domains

[Daryl Williams]

if this question is way of topic, i apologize
in advance. however i thought this might be
a knowlegable base to query regarding my
current research project.

i am looking for a way to alter the default
windows nt login behavior so that it may be
pointed at an ldap gateway. the intent is to
maintain on single authentication service for
disparate computing sysatems. i am aware of 
samba nt domain capabilties, but am also looking
for other alternatives.

thanks in advance,

daryl