[CentOS] CentOS 6 smb authentication?

I have some services on Centos5 boxes that use smb authentication against the Windows domain as a low-maintenance way to handle most of our office users for things that don't need home directories (web/file shares, etc.). Running authconfig is all it takes to add it to PAM, then adding mod_auth_pam to apache makes it work with that and local users. This all works without any particular involvement with the Windows group or administrative access there.

Is there a better way to do this on C6 that does not involve 'joining' the windows domain?

And is there a way to make samba (C5 or 6) work with Windows7 other than configuring every client to to send NTLM authentication when requested?