Found here.
To be able to run a program as a domain user when your current workstation is not part of the domain, use the following command line:

runas /netonly /user:domain\username "{program}"

Really nice when you want to connect remotely to a Sql Server with Windows Authentication, without being part of the remote domain.

Starting working on a new mission with MOSS 2007, I’ve setup a new development workstation.
I wanted to start with the latest products available at Redmond:

Windows Server 2008 R2
Sql Server 2008
Visual Studio 2008
Moss 2007 & Office 2007

with everything in 64 bits.