[Samba] notebook users question

[Adam Williams]

We have some staff that will be receiving notebook computers and will be 
doing field work (no internet access when not in the office).  In the 
office they will be in our domain.  But, how do I handle them logging 
into their computer when they are not in the office.  They won't be able 
to contact the domain server for their login username and password.  
What are my options?  Have them login as administrator/local user when 
in the field, or is there some way to have Windows XP on the notebooks 
cache their login username/password info and make it appear they are in 
the domain?