Log in to two domains

You can try with "NetSwitcher" to use two different network profiles.
Or for few tasks you can make a batch file if in both network is an DHCP server and you will set your laptop to use DHCP server.
Batch:
***************
rem start

SET /P something=
NET USE i: \\ServerName\ShareName /U:DomainName\Username %something%

rem end
************
something=password
ServerName=is a file server or print server
ShareName=is a share FolderName or a share PrinterName
DomainName=
UserName=
*************
You can add more lines like this to have access to more resources.
With this batch you will be prompted for a password or you can replace %something% with the "password".

JC, I have a very similar situation. I support about 10 guys who roam between three domains. The biggest question I would have is, do you need data from both domains at the same time. If not you cam simply join the new domain. Doing so will create a new profile on your notebook with User.DomainName in C:\Documents and Settings. When a computer is only part on a single domain, you will have just a folder with 'Username', bit subsequent domains will creates profiles with the domain name added. The problem is that the folders are not accessible when a in the other domain. Log into Domain A, and the Domain B proflile wont be accessible. So if you save to My Docs in Doamin A, you cant get them in Doamin B. I believe that you can simply create a new directory somewhere to save your stuff. I ended up creating trusts between the domains, which makes it possible to use a single profile, yet get the mappings and such of the domain he is on.
good luck....