If any of you have ever tried to access a SQL box on a network, from a laptop for instance, that is not part of the domain.
You will remember getting an error:
This problem also happens when you VPN connect to an outside network - and attempt access to the remote network through the VPN.Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection
You can get around this error, on WINDOWS XP PROFESSIONAL machines by:
START>CONTROL PANEL>USER ACCOUNTS
ADVANCED TAB...MANAGE PASSWORDS...
Click Add and then load the SERVER NAME of the SQL BOX on the other network and the WINDOWS AUTHENTICATION username and password that would give you authentication on that network!
From that point on you have credentials to access that server without actually logging in to that domain.
I was very impressed!