Too bad. However, based on your information I found this on Google:
http://sivel.net/2007/05/sso-apache-ad-1/
Thanks Filipe. Now I guess I can have a crack at this too.
I haven't tried this one, but make note it lacks NTLMv2 and group support which made it non usable in my environment. Like Filipe suggested mod_auth_ntlm_winbind addresses this but it appears it's not actively maintained and I got stuck configuring it and gave up...
jlc