I probably wouldn't have noticed this, but given that we recently had a SCFUG/UKCFUG meeting on Virtual Servers this little article on BetaNews caught my eye. Apparently, VMWare have released a beta of converter tool.
The tool allows you to create an image of a physical machine that you can use as a virtual machine. It also allows you to convert from other virtual machine images, such as Microsoft Virtual server.
At the moment the beta is on a hand picked basis, you need to fill in a survey, but it looks like it would be an exceptionally useful tool for getting started with virtual servers.