Different Desktops on WINDOWS 200

You are describing a Roaming Profile.
Please read Technet article How to Create and Copy Roaming User Profiles in Windows (Q142682):
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q142682
(please remove any spaces)

Now, I hope that your 2 domains are trusting one another. Because you will have to set the permissions on the profile folder structure to let both accounts (from the 2 different domains) to access the profile. So, if you save your profile on \\SERVER1 in DOMAIN1, make sure you set the Security on the profile so that your account in DOMAIN2 can access it (as well as your DOMAIN1 account).

It will be a little tricky getting both user accounts to access the same profile, but it is possible.

hope this helps

If they are completely different networks you can't use roaming profiles.

If the user names are the same it might use the same profile. Not positive about this.

You could use just one of your profiles. When you logged onto the other network you would get the message about using cached account information. You would then connect to network resouces on the other network with:
net use x: \\servername\share /user:domain\user password

You could also move your desktop items to C:\Documents and Settings\All Users\Desktop which would be on all profiles.