I was talking to a junior DBA a few months back who was complaining about not being able to secure a job because he didn't have enough experience. When I asked him if he knew about virtualization, he was lost. I told him how I have learned - and experienced - most of the skills I have using virtualization as my practice lab which started during the days of Connectix. Nobody can claim that virtual labs are not real-life experience because you are getting your hands dirty with real software, using real concepts and potentially troubleshoot real problems that may arise. It's one of the reasons why technical training is complemented with hands-on labs. Even when I was a developer, I used virtual machines to install a beta version of Visual Studio just to play around with it. It definitely is a must for every technology professional wanting to commit to continuous professional development