You might note from the large number of references to virtual machines (VMs) on this site I am a BIG fan of virtual machines. I build whole production network copies in private virtual spaces on my laptop for development, testing, troubleshooting, and of course presentations. I also love the snapshot ability to give me rollback from large sweeping changes. So as you can imagine I have a large dry-dock of virtual machines and I have number with me on a USB stick. I also have an extra full boat license for VMWare for my laptop.