I have put up a script that allows customisation of the batch file run when a Windows user logs into a Samba PDC. This script creates a unique login script based on the user's name and the groups they belong to. It ties nicely into any authentication method (file/LDAP/NIS/Kerebos/Samba) as long as PAM has been configured to pull user and group details from that source. The tutorial is online here:
Customised Netlogon scripts for Samba Howto
David Harrison's musings on collaboration and I.T.