I'm told I cannot do this???

[fw3308]

Look, I have the same issue. I have a company laptop which is on a workgroup and use it at work everyday even though we are set up with multi domains. Granted I am a domain admin but it can still work to access resources and printers. I plug into the lan with my laptop on a workgroup and then try to connect to a domain resource and then enter in my domain credentials that I wish to connect with when challenged. In this way I can get anything I need and still keep my laptop on a workgroup for use on my home network if necessary. It is an additional step but it is how I want to do it. I already have 3 pc's and a server in my office on various domains and just choose to keep the laptop in a workgroup.