I'm dealing with a special project at work that runs a bit of a risk of the configuration blowing up my Windows installation, so I'm not using my physical box (via remote connection/VPN), I'm using a VMWare clone of it. And now I'm using VirtualBox to run a virtual machine that I copied from someone else that I'm hoping has good config information. And my Mac is running Parallels VM to connect to the first VM.
So we have: Mac OS-X -> Parallels XP Pro -> VMWare XP Pro -> VirtualBox XP Pro.
So we have: Mac OS-X -> Parallels XP Pro -> VMWare XP Pro -> VirtualBox XP Pro.